Just when it looked as if Caley Thistle were destined for yet another draw, quality at both ends of the park ended their seven-match sequence at Firhill.
There had been little to separate the two sides with Partick and Inverness both guilty of missing more gilt-edged chances than the one which ultimately settled the match.
Tom Walsh’s stunning 71st-minute strike proved the difference, capping an excellent display from the winger who had provided much of Caley Jags’ creative spark on the day.
His work could have been undone within four minutes but the visitors kept their grip on the three points thanks to the increasingly thriving Mark Ridgers, who made an outstanding save to deny Blair Spittal’s penalty.
It is a valuable victory for the Highlanders, restoring their place in the play-off places and moving them to within eight points of leaders Ayr United, while extending their unbeaten league run to 24 matches.
The result and clean sheet was all the more impressive given the reshuffled defensive line John Robertson was forced to select.
He made two changes from the side which drew 2-2 against Ross County in the previous weekend’s Highland derby with Riccardo Calder having been sacked after being found guilty of assaulting a woman, and Shaun Rooney out with ankle ligament damage.
The enforced changes saw Jamie McCart drafted in to cover for Brad Mckay who was shifted to right-back, while Joe Chalmers occupied the left-back slot and saw his place in midfield taken by Charlie Trafford.
Although the run of draws had become a source of frustration for the Highlanders, it evidenced a resilience which had been sorely lacking from the Maryhill side in recent weeks, with the Jags coming into the game on the back of six straight defeats under new boss Gary Caldwell.
The hosts made a promising start with a fine lay-off from Kris Doolan setting up Jai Quitongo for a low shot that Ridgers gathered.
The visitors’ first meaningful attempt arrived when Liam Polworth’s free-kick was well stopped by Cammy Bell. They then enjoyed a strong end to the half with Walsh’s 20-yard strike forcing a parried save by Bell and Walsh turning supplier four minutes later with a cross that picked out Sean Welsh only for the former Thistle midfielder to be denied a goal on his Firhill return by Craig Slater’s saving block.
Caley Jags should have opened the scoring six minutes into the second half when the unmarked George Oakley steered his header over from close range.
The decisive moment came on 71 minutes when Walsh picked up the ball on the left before drifting inside on to his right foot, unleashing a 25-yard strike that Bell was unable to claw away from his top corner.
Partick were awarded a penalty four minutes later when Trafford was penalised for handball but Ridgers made the correct call low to his left to claw away Spittal’s spot-kick before standing tall to block Doolan’s follow-up on a day of relief for the Highlanders.