Never mind the title, Dundee United are now struggling to finish second in the Championship after losing an injury-time goal to Livingston.
The home side grabbed the lead on 22 minutes at the Tony Macaroni Arena through Scott Robinson’s well-placed shot before United sub Matty Smith equalised on 75 minutes.
Man-of-the-match Ryan Hardie, though, fired home in the first minute of stoppage-time to make this a heartbreaking defeat for Csaba Laszlo and his players.
They trail league leaders St Mirren by 14 points and that might stretch to 17 when the Buddies face Brechin City in Paisley. Almost as bad, they also sit six points adrift of the second-placed West Lothian team.
Tam Scobbie was back from injury for United and Scott McDonald was promoted to the starting line-up after being a substitute for the William Hill Scottish Cup defeat to Aberdeen 12 days previously.
Craig Slater and Smith, who both lined up against the Dons, dropped down to the bench.
The match survived a late pitch inspection, with concerns over a possibly frozen surface finally dismissed by referee Craig Thomson an hour before kick-off.
Livi had the first goal attempt, with United keeper Harry Lewis having to dive to push away Hardie’s 25-yard drive.
Lewis was called into action to thwart danger man Hardie again, this time going out to block from close range as the Livi man got his shot in.
On seven minutes, the busy United goalie was called upon again, this time to gather a dangerous cross from Nicky Cadden.
The visitors finally showed as an attacking force on nine minutes when frontman Emil Lyng burst forward stinging keeper Neil Alexander’s hands with a shot. Willo Flood followed that up with another strike but the danger was eventually cleared by Livi.
However, it was the home team that took the lead on 22 minutes.
United defender Mark Durnan conceded a freekick, which was taken by Raffaele De-Vita. The ball came into the box and, after Lee Miller played it back to him, Robinson clipped a shot just inside Lewis’s left-hand post.
The Tannadice team had to hit back and they came close on 33 minutes when Billy King raced up the left, cut inside then smacked in a 25-yard shot that was pushed past the post by Alexander’s outstretched arm.
Lyng needed treatment on the pitch after being caught on the ankle and was eventually replaced by sub Thomas Mikkelsen on 38 minutes.
With 44 minutes on the clock, Livi had the ball in the United net again but Hardie’s header off Cadden’s cross from the left was ruled out for offside against the striker.
The Tangerines, who replaced Gillespie with Smith at the interval, took a while to warm up in the second half.
On 52 minutes, Durnan was booked for chopping down Scott Pittman and Cadden fired the resultant freekick just wide for the hosts.
United were enjoying a decent spell now and they came close to levelling when Flood left fly with his left foot from 30 yards only for Alexander to push the ball over.
From the corner, King’s cross from the left was met by the head of Scobbie and went just the wrong side of the Livi post.
Hardie was causing problems whenever he got near the ball and Lewis did well to get down and smother another strike from him on 67 minutes.
The hosts had the ball in the net for a third time on 72 minutes but the flag had gone up again against Robinson before, finally, there was something to cheer about for the 600-plus away fans when the Tangerines made it 1-1.
It was game on thanks to sub Smith, who fired a superb shot past Alexander from 16 yards after a sweeping move involving Flood and Sam Stanton.
It was the 20-year-old’s first league goal for United and now all they needed was the winner.
The Tangerines had their tails up and another great piece of play saw Stanton burst into the box only his cross to strike teammate Mikkelsen.
With three minutes remaining, Stewart Murdoch’s shot was deflected just wide of the Livi goal before there were claims – ignored by ref Thomson – when Mikkelsen went down inside the box.
It looked like United might sneak it but instead Hardie blasted the ball home from 20 yards with the clock showing 91 minutes.
It was a hammer blow and one that will severely test this United squad in what is left of another challenging campaign.
Livingston: Alexander, Lithgow, Halkett, Gallagher, Robinson, Pittman, Byrne, De-Vita, Cadden, Miller, Hardie. Subs not used: Maley, Buchanan, Longridge, Jacobs, Mullin, Boyd, McMillan.
Dundee United: Lewis, Murdoch, Scobbie, Durnan, McDonald (McMullan 81), King, Stanton, Flood, Robson, Gillespie (Smith 46), Lyng (Mikkelsen 38). Subs not used: Deniz, Quinn, Slater, Mason.
Referee: Craig Thomson.