Caley Thistle went down 2-1 to Hearts despite a brave fightback against the Championship title favourites at Tynecastle.
The Jambos had appeared to be cruising after second half goals from Steven Naismith and Liam Boyce gave them a two-goal cushion.
Although Inverness hit back late on through Aaron Doran, Hearts held on to maintain their 100% start to the campaign.
Inverness named an unchanged side from the team which recorded its first victory of the campaign against Arbroath the previous weekend.
Inverness started brightly, with an early Nikolay Todorov header comfortably gathered by Craig Gordon.
The Jambos threatened on 11 minutes though, with Andy Halliday threading a pass through for Stephen Kingsley, whose cutback was too far behind the run of Liam Boyce.
Former Ross County forward Boyce had an even better chance seconds later when Craig Halkett nodded an Olly Lee free-kick across goal, however the Northern Irishman headed the effort wide.
Both sides looked to carve out openings without creating too many clear cut chances, with Wallace Duffy making an excellent headed intervention to deny Steven Naismith at the far post, while at the other end Kai Kennedy’s surging run took him past Halkett but his attempted through ball had too much on it for Todorov.
Although Inverness enjoyed a decent spell of play they were unable to threaten Gordon’s goal, with the Jambos seeing efforts from Michael Smith and Peter Haring narrowly miss the target before the interval.
The home side made the perfect start to the second half, taking the lead within 60 seconds of the restart. Kingsley was released down the left flank before whipping the ball into the middle, where skipper Naismith was on hand to acrobatically volley past Mark Ridgers.
Inverness looked for a quick response, with lively winger Kai Kennedy seeing an effort deflected wide after picking up a loose ball.
Robertson introduced Shane Sutherland in place of Roddy MacGregor in the push for a leveller, however Robbie Neilson’s men doubled their lead on 69 minutes. Olly Lee broke down the inside right channel before cutting the ball across goal, where it was met by a deft near post flick by Boyce to beat Ridgers.
Hearts looked to inflict further damage, with substitute Aidy White crashing a strike off the crossbar.
Inverness set up a tense finish when substitute Doran nodded home a James Keatings delivery to make it 2-1, however they were unable to follow up with a leveller.
