Caley Thistle fell to a 1-0 defeat against Morton at Cappielow, meaning they remain six points adrift of the Championship promotion play-off places.
A first-half penalty from Gary Harkins was enough for the Greenock outfit to triumph, with defender David Raven sent-off in the build-up.
It was a poor display from Inverness, with the best efforts of their goalkeeper Mark Ridgers saving them on numerous occasions even prior to Raven’s dismissal.
The defeat inflicted a first away defeat since a 2-1 loss to Dumbarton in September on John Robertson’s men, with the victory moving Morton up to fourth.
Caley Jags made one change from the side that defeated Dumbarton 1-0 the previous weekend, with Iain Vigurs returning from suspension to replace Charlie Trafford.
Inverness had recorded 10 clean sheets in their last 11 matches ahead of the trip to Inverclyde, however the opening stages of the first-half provided the Caley Jags rearguard with arguably its biggest test during that period.
Although Inverness threatened first, when Carl Tremarco headed Liam Polworth’s corner wide, Morton were the dominant side in the opening 45 minutes. They were inches from taking the lead on 11 minutes when Harkins’ free-kick clipped the top of the crossbar, after Tremarco had been penalised for taking down Jai Quitongo dangerously close to the penalty area.
Inverness goalkeeper Mark Ridgers was called into action for the first time on 13 minutes, making a decent parried save to deny Quitongo after he had spun past Coll Donaldson, before Ridgers made an even better save to deny Robert Thomson just seconds later.
Ridgers had to be alert once again on 16 minutes, beating away another Harkins free-kick which the midfielder bent around the wall.
Morton’s front two were causing the visitors plenty problems and they combined once again on 21 minutes, with Thomson flicking on for Quitongo, but Ridgers was out rapidly to thwart the danger.
Jim Duffy’s men did take the lead just a minute later, with a penalty required to beat the impressive Ridgers. It was a double blow for the Highlanders, as Raven was dismissed by referee Colin Steven for pulling down Thomson as the attacker bore down on goal. Harkins made no mistake from the spot, sending the penalty into Ridgers’ bottom-right hand corner despite the goalkeeper guessing correctly.
The loss of Raven prompted a reshuffle from Robertson, who sacrificed one of his main attacking threats in Connor Bell in order for Collin Seedorf to slot in at right back.
Inverness’ chances were few and far between in the first period, but their nearest attempt fell to midfielder Joe Chalmers who guided Jake Mulraney’s cross wide of target following good work down the right flank by the Irishman.
Morton continued to threaten though, and they were denied a second when Gary Oliver’s header was hacked off the line by Polworth, before Thomson saw a header tipped away by Ridgers.
Inverness ended the half with a headed opportunity of their own four minutes before the break, however skipper Vigurs could not find the target from Polworth’s set-piece delivery.
With the wind behind Caley Jags, Robertson would have hoped for a better showing from his side in the second-half despite their numerical disadvantage, however chances dried up for both sides after the break.
Robertson opted to take a more direct approach as the game reached its closing stages, by withdrawing John Baird and Mulraney to make way for Trafford and George Oakley.
Englishman Oakley had an opportunity to pull Inverness level on 78 minutes, however he failed to get enough contact on his header from Vigurs’ deep delivery, however there was to be no way through for Inverness.