A stoppage-time goal from Nicky Clark snatched a point for Dunfermline in a 2-2 draw with Caley Thistle.
A solo goal from Nathan Austin three minutes into the second half looked to have decided the contest but Clark glanced in Joe Cardle’s free-kick in the 94th minute to ensure a share of the spoils.
Andy Ryan put Dunfermline in front after 12 minutes but a swift rebuttal from the Highland capital club through Joe Chalmers levelled the scores.
January signing Austin made his telling contribution at the start of the second half before Clark breached the Caley Jags backline in the fourth of six injury-time minutes.
It means Inverness now must beat Livingston on Tuesday and Morton next weekend, while hoping Dumbarton take points off the Pars next Saturday.
Caley Thistle made three changes from the 1-0 win over Dumbarton on Wednesday. Gary Warren missed out with a calf injury and Iain Vigurs was suspended, while Riccardo Calder dropped to the bench. In came Collin Seedorf, Carl Tremarco and Charlie Trafford. Dunfermline brought in Ryan for Declan McManus in their only change.
Ryan put the Pars ahead on 12 minutes with a shot from the left side of the area that appeared to go through Mark Ridgers’ gloves and in.
It was a less than perfect start for Inverness, who needed to win to keep up their late charge for the play-offs. They got the instant response they craved when Chalmers curled home a free-kick from 25 yards via the inside of the post.
The hosts seemed to be getting the bit between their teeth, with Aaron Doran doing well to work some space for himself on the edge of the box but his left-footed effort rolled narrowly wide.
Dunfermline were well-backed by 700 travelling supporters, with a win for Allan Johnston’s side being enough to confirm their spot in the play-offs. Had Fraser Aird been more decisive after Ryan got the better of Brad Mckay, they could well have retaken the lead.
Chalmers the chance to add to his tally three minutes before the break, as the Pars defence allowed him to stroll forward from midfield and take aim, but his shot was off target.
There was still time for Nathan Austin to spin Jean-Yves M’Voto and head towards goal but the angle worked against him, as his shot was smothered by Lee Robinson in the Dunfermline goal.
Austin delivered his stunner three minutes into the second half as he picked the ball up on the right flank, drove past four Dunfermline defenders and squeezed the ball past Robinson at his near post.
The momentum was with the home side and Carl Tremarco was next to come close on 52 minutes, rising to meet Liam Polworth’s corner at the far post but glancing wide.
Johnston’s men had struggled to fashion any chances until the 68th minute, when substitute Joe Cardle dragged his shot wide from the edge of the box with Ridgers scrambling.
Declan McManus ought to have done better when the ball broke to him unmarked on 77 minutes but he did not get a clean contact on his strike, allowing the Caley Thistle defence to clear.
A glorious counter-attack gave the home side the opportunity to finish the job, with Doran picking out Daniel MacKay at the far post and in front of the North Stand, he rolled his shot agonisingly wide of the far post.
Caley Thistle looked to have held on for a vital victory but they were cruelly denied, with Clark’s stoppage-time goal sparking wild scenes in front of the travelling fans.