Crusaders left in a sweat after going down to Portadown
Portadown 1-0 Crusaders
Crusaders still have some distance to travel before they can get close to the promised land.
This defeat, coupled with Linfield's victory at Glentoran, has cut the Crues' lead at the top of the Danske Bank Premiership to six points with four games remaining.
The Blues will have fresh belief while new doubt will be cast on the Shore Road men's pursuit of a first league title in 18 years.
With Linfield still to wrestle with the leaders, the championship race is still very much alive, just when it looked like drifting to an inevitable conclusion.
Crusaders' superior goal difference gives them an added cushion but there will certainly be a few more nerves around Seaview.
Tim Mouncey's 85th minute header settled a dull contest and leaves the Ports now level with Clifttonville and Glenavon in the race for European qualification.
League titles have to be earned and Crusaders still have plenty of work to do while Linfield are asking questions and turning up the heat.
The Crues were without suspended skipper Colin Coates while Paul Heatley's wedding explained his absence. The Ports, with one eye on the Irish Cup final, were without Michael Gault, Mark McAllister, Garry Breen and the suspended Robert Garrett, while Darren Murray started on the bench.
The visitors started in confident fashion and Richard Clarke looked away in frustration as his teasing cross along the six yard box in the sixth minute failed to pick out dark blue jersey.
Seconds later, Clarke's long range drive flew over the crossbar as the visitors looked to inflict an early blow. Gavin Whyte tried his luck from a tight angle in the 11th minute but his drive missed the target.
Both sides struggled to get into their rhythm and the opening 20 minutes were uneventful. Chris Casement's long range free-kick was also wayward as the game cried out for a moment of magic. Whyte attempted to deliver but his effort from distance was always going wide.
The Crues had a penalty shout on 32 minutes when Ken Oman appeared to tug back Timmy Adamson but referee Raymond Hetherington wasn't impressed.
Fra McCaffrey's goal for Glentoran against Linfield lifted spirits in the stands but the Shore Road side were still struggling to hit top gear.
Jordan Owens just failed to gather Barry Molloy's inviting pass as the visitors started bossing the midfield but neither side had inflicted damage by the half-time refreshments.
Crusaders started the second half brightly and Oman was in the right place to clear Adamson's drive off the line.
Portadown had their moments and Tim Mouncey fired a volley across the penalty area which rang a few alarm bells.
The hosts missed a great chance in the 82nd minute when Peter McMahon drove a shot from 10 yards over the crossbar.
Despite fielding an under strength side, Ronnie McFall charges held their own against a side with title winning ambitions.
And in the 85th minute they stunned the visitors by storming in front. Man-of-the-match Mouncey headed home from a Sean Mackle cross. It was the game's decisive moment and secured the victory.
The Crues tried to respond but Clarke's lob over stranded keeper David Miskelly was diverted off the line by Jordan Lyttle.
Portadown will be thrilled with this result, especially considering the players who were unavailable, but Crusaders' first league defeat since December 6 - against Portadown - threatens to crush their dream right at the death.
They think it's all over. It isn't yet.
Portadown: Miskelly, Casement, Redman, O'Hara, McMahon, Mackle, Mouncey, Oman, Twigg, Conaty (Soares 66), Lyttle. Substitutions: Soares (Conaty, 66 mins).
Crusaders: O'Neill, Burns, Magowan, Adamson, Robinson, Caddell, Molloy (Hanley 78), McClean (O'Flynn 93), Owens, Clarke, Whyte (O'Carroll 87). Substitutions: Hanley (Molloy, 78 mins), O'Carroll (Whyte, 87 mins), O'Flynn (McClean, 90 mins).
Man of the match: Tim Mouncey
Match rating: 5/10
Referee: Raymond Hetherington (Dungannon)