Second-half goals from Gary Cahill and Eden Hazard were enough to finally down second-placed Spurs' charge but the night, and season, belongs to Leicester and their Italian manager.
Ranked as 5,000-1 outsiders at the start of the campaign, doubts were raised over whether Ranieri could stave off a battle against the drop when he was appointed as Nigel Pearson's successor on July 13.
Now, 294 days later, he had the luxury of jetting back home to Rome to have lunch with his 96-year-old mother before returning to the East Midlands a hero.
The 64-year-old, though, was far from the only knight in shining armour at the King Power Stadium this term.
Some of Leicester's unlikely stars were watching events unfold at striker Jamie Vardy's house on an evening of high drama.
Foxes fans have coined the 'Jamie Vardy's having a party' chant this season, and the England striker appeared to be actually throwing one at his Melton Mowbray home.
Pictures from the Daily Mail appeared to show a number of players such as Christian Fuchs, Robert Huth, Wes Morgan and Shinji Okazaki arrive at Vardy's home, while a number of supporters also gathered outside the gates of the house.
Vardy began his senior career at Stocksbridge Park Steels after being rejected by Sheffield Wednesday as a teenager and was playing non-league football for Fleetwood in 2012.
The 29-year-old, who claimed the Football Writers' Association player of the year award on Sunday, has gone on to score 24 goals for club and country this season and looks set to lead the line for England at Euro 2016.
Riyad Mahrez's 17 goals and 11 assists saw him crowned PFA player of the year, capping the Algerian's astonishing accent from the French second division as recently as 2014.
Goalkeeper Kasper Schmeichel, defenders Morgan and Danny Simpson and midfielders N'Golo Kante and Danny Drinkwater were also recognised by the voters in the FWA poll.
Winger Marc Albrighton, speaking after Sunday's 1-1 draw against Manchester United at Old Trafford which edged the Foxes closer to their first-ever top-flight title, said: "We've got that never-say-die attitude. I think that's won us a lot of points this season.
"Early on this season you've got the draws at Stoke and Southampton, we were 2-0 down in both of them, and 2-0 down in the home game against Villa.
"So that showed our character early in the season and we've continued to do that. We've gone behind at Old Trafford, which is a daunting place. It's a big pitch and the fans are behind them, but credit to the lads, we carried on going, got the equaliser and held on."
Leicester lost 19 games in last season's bid to escape relegation yet, under Ranieri, they have tasted defeat just three times in the Premier League.
They have gone to Manchester City and Tottenham and won, while an unbeaten run since mid-February proved beyond any doubt Ranieri's side had the nerve to finish the job.
Albrighton admitted after the thrilling draw with United that a title success would take time to register.
"I don't think it will for a while," the former Aston Villa winger added. "It might sink in later on in the summer. If we can wrap up the title it will be such a fantastic achievement and maybe then it will sink in."
Seven years ago, to the day, after the Foxes rounded off their League One title-winning campaign with a 3-0 win away at Crewe, they can now savour the proudest moment in the club's history.
'Greatest achievement in sporting history'
Former Leicester midfielder Robbie Savage believes the Foxes clinching the Barclays Premier League title is the "greatest achievement in sporting history".
Leicester were confirmed as champions after Eden Hazard's late strike earned Chelsea a 2-2 draw with Tottenham that meant Spurs could not catch the Foxes.
Savage told Radio 5Live: "It's going to be one unbelievable night for Leicester. Those fans have been with that team through thick and thin.
"I was with Muzzy Izzet at the weekend he was scoring goals in League One not all that long ago and now they're Premier League champions. The greatest achievement in sporting history. I don't think anything betters this. It's incredible.
"They've proved a lot of people wrong. I was a massive sceptic of Claudio Ranieri. I didn't think they could win it but they've proved me and a lot of people wrong and they thoroughly, thoroughly deserve it. What an amazing night."
Former Leicester striker Tony Cottee echoed those sentiments about Ranieri, telling Sky Sports News: ''It was a big decision when Nigel Pearson left and Claudio Ranieri came in and lots of people, myself included, were unsure whether he would be the right man but he's been absolutely fantastic.
''When he came into the club it would have been easy to make lots of changes but he's a clever manager and he obviously realised he had some good players with a good team spirit.
''He's obviously got some stand out players like Riyad Mahrez and Jamie Vardy but they all work really well as a team and obviously they have had that little bit of luck that you need, as they haven't had too many injuries or suspensions.
''They've been the best team and that's the biggest compliment you can give them - not the best individuals, the best team.
''They were 5,000-1 at the start of the season and you couldn't really even see them finishing in the top half, let a lone win the league.
''It's great for football because everyone next season will start the season thinking well Leicester did it last season, why can't we do it this year?''
It has been a unpredictable roller-coaster of a season for Leicester after they clinched the Barclays Premier League title having lost just three times all campaign.
They have been the outstanding team of the year and Press Association Sports charts their rise from 5,000-1 title outsiders to champions.
Leicester begin with a convincing 4-2 win over wretched Sunderland in what many saw as a first-day survival battle.
Riyad Mahrez scored twice while Jamie Vardy netted his first of the season in a sign of things to come.
A 2-1 win at West Ham followed before a 1-1 home draw with Tottenham and a 1-1 draw at Bournemouth as a Vardy penalty began his record-scoring streak.
The month started with two comebacks as the Foxes fought back from 2-0 down to beat Aston Villa 3-2 thanks to a Nathan Dyer's late winner.
A 2-2 draw at Stoke came after they were again 2-0 down before Mahrez and Vardy hauled them level in the second half.
Their first defeat of the season came in a 5-2 thumping at home to Arsenal, perhaps the only time they were outclassed despite Vardy's two goals.
Leicester recovered from the Gunners' defeat to win 2-1 at Norwich thanks to Vardy and Jeff Schlupp.
Another 2-2 comeback draw was secured at Southampton as Vardy scored twice and they finally kept a first clean sheet of the season with a 1-0 win over Crystal Palace - prompting boss Claudio Ranieri to fulfil his promise and buy the squad pizza.
A 3-2 win at West Brom moved them up to third in the Premier League as Vardy continued his scoring streak by netting in his eighth game in a row.
Vardy broke Ruud van Nistelrooy's Premier League scoring run by netting in his 11th straight match, the opener in their 1-1 draw with Manchester United.
Before then, N'Golo Kante and Vardy clinched a 2-1 win over Watford and a 3-0 victory, with goals from Vardy, Shinji Okazaki and Leonardo Ulloa, at Newcastle sent the Foxes top.
Vardy's scoring run ended in Leicester's 3-0 win at Swansea as Mahrez picked up the slack with a hat-trick at the Liberty Stadium.
In their next three games the Foxes beat Chelsea 2-1 and Everton 3-2 before just their second defeat of the season, losing 1-0 at Liverpool.
They finished 2015 with a 0-0 draw with Manchester City, leaving them second - behind Arsenal on goal difference.
Another home stalemate with Bournemouth kicked off 2016 as Leicester wobbled after Artur Boruc saved Mahrez's spot kick to leave them two points behind leaders Arsenal.
But Robert Huth's late header gave the Foxes a crucial 1-0 win at Tottenham and ended a run of three games without a goal.
A 1-1 draw at Villa took them top - a position they never lost again - despite Mahrez's second successive penalty miss and a 3-0 win at home to Stoke wrapped the month.
It was a month where dreams started to become a reality as a stunning Vardy double - including a wonderful 30 yard volley - dispatched Liverpool 2-0.
But it was the 3-1 win at Manchester City - earned through Huth's brace and Mahrez's silky effort - which moved them five points clear at the top.
Danny Welbeck broke Leicester hearts with a last-minute header in a 2-1 defeat at Arsenal but Ulloa's 89th minute winner then earned a barely-deserved 1-0 victory over Norwich.
Fans starting cashing in their bets as one supporter settled for £72,000 following his £50 bet on the Foxes to win the title at the start of the season, when they were 5,000-1.
A 2-2 draw with West Brom briefly stalled momentum - Craig Gardner's free kick denying Leicester victory - before Ranieri's side started to grind out results.
Watford, Newcastle and Palace were all beaten 1-0 as Leicester stretched their lead to eight points and proved they could handle the growing pressure.
The run continued as captain Wes Morgan scored his first goal of the season to beat Southampton 1-0.
Vardy then ended ended a six-game drought to score twice - his 20th and 21st goals of the season - as they cruised past struggling Sunderland 2-0.
Leicester's title bid suffers a minor blow after a 2-2 draw with West Ham - when Jamie Vardy was controversially sent off after a second yellow for diving - but they then beat Swansea 4-0 without him.
Missing Vardy, City went to Manchester United and got a 1-1 draw thanks to Morgan's goal. The next night, Chelsea drew with Tottenham and the job was complete.
Players that guided team to title
Leicester have shocked the Barclays Premier League but claiming the crown - the first top-flight title in their history.
They have lost just three times in the season and England striker Jamie Vardy has netted 22 league goals. Here, Press Association Sport looks at five players who have played a key part in the Foxes' title success.
The record-breaker has enjoyed a fairytale season and an astonishing rise after joining the club from Fleetwood in 2012.
Just four years ago he was helping the Cod Army out of the National League and this summer he will, barring injury, be in England's Euro 2016 squad.
He set a new Premier League record by scoring in 11 straight games, became the first Leicester play since Gary Lineker in 1985 to net 20 top flight league goals and was nominated for PFA Player of the Year.
The PFA Player of the Year is one of the hottest properties in football after a stunning season having scored, so far, 18 goals, assisted 11 more.
Two goals in the opening day win over Sunderland set the tone and while he has only netted four times in his last 18 games he remains one of Leicester's stars.
Boss Claudio Ranieri has always said he would allow players to leave if they wanted to and Barcelona have been linked with the Algeria winger.
The midfielder was unknown when he arrived from Caen for a reported £5.6million last summer but was a PFA Player of the Year nominee and has become a France international.
Head of recruitment Steve Walsh pushed Ranieri to sign the 25-year-old and he has helped fill the void left by Esteban Cambiasso, who left last year.
Ranieri has reaped the rewards with relentless Kante doing the dirty work for Vardy and Mahrez to let loose going forward.
His form earned the midfielder an England debut in March and pushed him to the brink of Roy Hodgson's Euro 2016 squad.
Perhaps overlooked before being called up for the Three Lions as Kante, Mahrez and Vardy grabbed the plaudits but he has been central to Leicester's success.
A deep-lying playmaker he has complimented Kante with similar all-action displays in front of the defence.
A Premier League veteran, the 31-year-old's career looked to be winding down when he joined Leicester from Stoke in January 2015.
But he has been a rock at the back for the Foxes and has also scored crucial goals, including the winner at Tottenham and a brace at Manchester City.
He won two league titles with Chelsea in 2004 and 2006 under Jose Mourinho having also played under Claudio Ranieri at Stamford Bridge.
Fairy tale story
In November 2014 Claudio Ranieri was sacked by Greece.
"A most unfortunate choice of coach," said the FA after defeat to the Faeroe Islands cost Ranieri his job.
The Italian lasted just five games, winning none, and left with the contempt of a nation and their Euro 2016 hopes in tatters.
But finally, he has a prize which has eluded him for 30 years.
An improbable, stunning and almost unfathomable Barclays Premier League title with Leicester ends his runner-up tag after second place finishes with Chelsea, Juventus, Roma and Monaco.
His first top-flight title after 16 jobs, including two spells at Valencia, comes at the most unlikeliest of clubs.
When Vichai Srivaddhanaprabha bought Leicester in 2010 he told the players - who felt he was optimistic having just seen Nigel Pearson end his first spell by joining Hull - they would win the Premier League in five years.
The Thai billionaire was a year out but even he would have struggled to believe the Foxes would win as they sat 5,000-1 outsiders to win the league in August.
Ranieri himself was one of the favourites to be sacked when he replaced Pearson in July, ending an 11-year exile from the English game.
Some sneered, others questioned the appointment of a 64-year-old who had not managed in England since he was replaced by Jose Mourinho at Chelsea.
But it is Mourinho's record he breaks, winning the Premier League just 294 days after being appointed. Mourinho took 332 days to achieve the same feat at Stamford Bridge.
Ranieri inherited a squad who had won seven of their final nine games last season to survive under Pearson, who returned from Hull in 2011 and won the Championship three years later.
The Tinkerman was expected to change but his best move as boss was to maintain the status quo.
Craig Shakespeare and Steve Walsh, Pearson's long-time lieutenants, stayed - as did the squad. N'Golo Kante and Shinji Okazaki arrived after Christian Fuchs signed before Pearson was dismissed.
They were likely to join regardless of the boss but Ranieri listened to head of recruitment Walsh, who he worked with at Chelsea, rather than ripping up the blueprint.
Pearson's legacy of spirit, work and hunger remains but Ranieri and his staff have added the touch of panache and class which has elevated them above the establishment.
Danny Drinkwater has become an England international, two 30-something centre-backs in Robert Huth and Wes Morgan form one of the best partnerships in the league and Riyad Mahrez won the PFA Player of the Year.
Jamie Vardy scored five goals last season, this term he will go to Euro 2016 with England having become the first Leicester player since Gary Lineker in 1985 to score over 20 top-flight goals.
Pearson nurtured them but under Ranieri they have blossomed.
He allowed the dressing room to run itself, headed by skipper Morgan who handles any issues the players have an acts as a reliable mouthpiece for the squad.
He gained their trust, difficult given their fierce loyalty to Pearson, and has shielded them from the spotlight.
Pearson's brash nature took some of the heat, as the headlines fell on him following bizarre ostrich comments and touchline spats with fans, but Ranieri's charming and approachable manner made him the anti-Pearson.
Rather than getting into rows with journalists, he shakes hands with every one before his pre-match press conference.
He also has a picture of every Premier League manager on his office wall because he wants them to feel welcome.
Offers of pizza for clean sheets - when Leicester finally managed their first shut out of the season in October - are as bizarre as they are shrewd.
The squad bonded further under Ranieri, who would routinely give players unscheduled days off if he felt they were tired. He looked after his team.
When Okazaki passed his English exam in April Ranieri made a point of celebrating it, even pretending he had called the team meeting especially.
That was in private but his calculated public game kept a lid on expectations and he ticked off their ambitions only when it was right.
The former Inter Milan boss comes across as everyone's favourite uncle but the wheels are always turning.
Only when Leicester had four games left did he admit they could win the title.
Tottenham's slip 72 hours after Ranieri had made his ambitions clear gave the Foxes a clear run to the league and it is one Leicester and the Italian deserve.
A maiden major title represents the most glorious of triumphs for a man who began his managerial career with Lametini in 1986.
Under two years ago he was on the scrapheap, a failure with Greece, leading to their FA's damming "unfortunate" barb.
Fortunately for Leicester, Ranieri has completed his resurgence.
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