Southampton substitute Shane Long headed a late equaliser to deny Steve McClaren a winning Barclays Premier League start in charge of Newcastle.
Goals from Papiss Cisse and new boy Gini Wijnaldum had put the Magpies in command after Graziano Pelle's 24th-minute opener for the visitors at St James' Park.
But Long - a 65th-minute replacement for Jay Rodriguez, who was making his first top-flight appearance since April 2014 - rose to power home a cross from the Dusan Tadic with 11 minutes to go to ensure a 2-2 draw.
And it could have been worse for McClaren who watched Saints striker Sadio Mane miss two glorious chances to win it in the dying seconds.
First Mane saw a shot blocked by Jack Colback and deep into injury time another clear effort drifted inches wide of the beaten Tim Krul's right-hand post.
Wijnaldum will have impressed McClaren from the start, whipping in a dangerous second-minute free-kick then missing another golden opportunity when his shot was headed clear by Steven Davis.
The visitors, bossed for the day by Erwin Koeman with brother Ronald at home nursing an Achilles injury, started slowly with Tim Krul saving their best early chance from new signing Cedric Soares.
But they snatched the lead in the 25th minute when the impressive Cedric crossed from deep on the right and Pelle out-jumped the somewhat static Chancel Mbemba to power his header past Krul.
Saints survived a second handball shout on the half-hour after Cisse spurned a fine opportunity to level for Newcastle, then Rodriguez almost marked his return with a second for Saints as he sent a looping header just over.
Davis came to Saints' rescue once again in the 37th minute when he booted a Fabricio Coloccini effort off the line, but Newcastle's increased momentum brought them a deserved equaliser three minutes before the break.
There was an element of good fortune about the goal, with Massadio Haidara's cross taking a big deflection off Mane and catching out keeper Maarten Stekelenburg, allowing Cisse to bundle home from point-blank range.
Tadic scooped over the bar in first-half injury time before a blistering start to the second period put the Magpies in front.
First Maya Yoshida should have grabbed a second for Saints when his effort from close-range somehow ricocheted to safety off the out-stretched leg of a diving Krul.
And the hosts seized their second chance by pouring straight up to the other end where Gabriel Obertan crossed from the right for Wijnaldum to power past Stekelenburg.
The goal gave Newcastle some semblance of control although their momentum was hit when Vurnon Anita was stretchered off just past the hour-mark after falling awkwardly following a fair challenge from Mane.
And new striker Aleksandar Mitrovic certainly made an impression when he was booked for a scything challenge on Matt Targett less than a minute after coming on to replace Cisse 15 minutes from time.
Saints capitalised when Long rose above another static home rearguard to head his side's second from an inch-perfect Tadic cross - but they will leave the north-east disappointed after Mane's two near-misses at the end.
TWEET OF THE MATCH
"Good Luck for the Boys! #NEWSOU. Total confidence in the Staff and Players! #WeMarchOn"
Injured Southampton boss Ronald Koeman (@RonaldKoeman) was feeling positive about the match
Tim Krul: 7 (out of 10)
Fabricio Coloccini: 7
Jack Colback: 7
Gini Wijnaldum: 8
Moussa Sissoko: 6
Vurnon Anita: 6
Papiss Cisse: 7
Gabriel Obertan: 6
Chancel Mbemba: 5
Massadio Haidara: 7
Daryl Janmaat: 6
Cheick Tiote: 6
Aleksandar Mitrovic: 6
Siem De Jong: 6
Maarten Stekelenburg: 6
Cedric Soares: 7
Maya Yoshida: 7
Jose Fonte: 7
Steven Davis: 8
Jay Rodriguez: 6
Sadio Mane: 6
Dusan Tadic: 8
Victor Wanyama: 6
Graziano Pelle: 7
Matt Targett: 6
Cuco Martina: 6
Shane Long: 7
Gini Wijnaldum: The Newcastle new boy was a solid presence throughout, marshalling the Magpies' midfield and exuding plenty of promise for the season ahead. His goal - a powerful header from Gabriel Obertan's 48th minute cross - was everything he deserved for an impressive performance.
MOMENT OF THE MATCH
The game turned on its head in a spectacular 30-minute spell early in the second half. First Tim Krul somehow managed to save Maya Yoshida's point-blank effort - then the Magpies streamed upfield where Obertan crossed for Wijnaldum to put the hosts in front.
VIEW FROM THE BENCH
McClaren will have been quietly encouraged by his side's sense of urgency - and in particular Wijnaldum's impressive debut. For Saints assistant Erwin Koeman - replacing his injured brother Ronald - delight at getting back in the match will have been tempered by Mane's two late misses.
MOAN OF THE MATCH
There was no disputing Newcastle striker Aleksandar Mitrovic was keen to make an immediate impression on his debut. But his scything challenge on Matt Targett which earned him a yellow card less than a minute after replacing Papiss Cisse in the 75th minute was wholly unnecessary.
WHO'S UP NEXT?
Swansea v Newcastle (Premier League, Saturday 15 August)
Southampton v Everton (Premier League, Saturday 15 August)