Caley Thistle’s promotion play-off hopes were ended as they fell to a 3-0 defeat against Championship title winners Hearts at Tynecastle.
Three first half goals were Inverness’ undoing, with Gary Mackay-Steven netting a double each side of an Aaron McEneff strike.
Dunfermline’s 4-3 victory over Arbroath means Caley Jags now cannot catch the Pars, who they are four points behind going into their final game of the season at home to Ayr United on Friday.
Inverness made just one change from the side which drew 1-1 with Dundee on Tuesday, with Cameron Harper drafted in to replace Brad Mckay, whose appeal against the red card shown to him against the Dark Blues was unsuccessful.
Midfielder Scott Allardice saw his dismissal in the same game reversed however, meaning he was able to retain his place in the side.
Both sides made a lively start, with Scott Allan fizzing a powerful drive just over after being picked out by a Sean Welsh corner, while at the other end Armand Gnanduillet saw a header cut out by Mark Ridgers.
The Jambos took an impressive lead on six minutes however, with Mackay-Steven picking the ball up on the right before weaving his way into a shooting position, with the former Aberdeen winger drilling low past Ridgers to claim his first Jambos goal.
It got even worse for Caley Jags just three minutes later, with Liam Boyce teeing up McEneff whose deflected low effort trickled low into Ridgers’ bottom corner to double the hosts’ lead.
Inverness looked to respond to the early setback however the Jambos continued to pose a threat in attack, with Gnanduillet unable to steer a tempting Peter Haring delivery goalwards.
The Highlanders had a glimpse of goal on 29 minutes when David Carson picked out Nikolay Todorov with a floated cross from the right, however the Bulgarian could not get enough of a connection to direct it on target.
Caley Jags were showing more attacking threat, with Daniel MacKay seeing a low strike from the edge of the box held by Craig Gordon.
The Highlanders’ hopes of a comeback were virtually ended on 31 minutes however, when a mix up between Ridgers and Robbie Deas in dealing with a Gnanduillet flick on allowed Mackay-Steven to nip in and fire home.
Ridgers was called into action again before the break, getting down low to hold a McEneff strike from distance.
McCann brought on Roddy MacGregor in place of Allardice as Caley Jags looked for an early second half breakthrough, with Todorov seeing an effort from an acute angle saved by Gordon, while Harper was well off target with a strike from distance.
McCann was shown a red card on the hour mark, following a heated argument with counterpart Robbie Neilson after a Welsh foul on Boyce, with the Caley Jags interim boss watching the remainder of the match from the stand.
Hearts came inches from adding to the scoresheet when Boyce knocked a Mackay-Steven cross off the post from close-range, while at the other end Allan struck an effort straight at Gordon following a neat run.