Match ends, Inverness CT 1, Partick Thistle 2.
A double from Kris Doolan ensured Inverness suffered their first home defeat of the season in a controversial match in the Highlands.
Doolan put Partick ahead, firing low under Dean Brill after 20 minutes.
Aaron Doran thought he had levelled, but the goal was ruled out after officials ordered a corner be re-taken.
Gary Warren's header restored parity after the break, but hosts goalkeeper Brill fumbled a cross to give Doolan a simple tap-in to claim the win.
With Partick having encounters against Aberdeen and Celtic to come, manager Alan Archibald will have been delighted to grab a vitally important victory.
But where luck had perhaps evaded them in recent weeks, they certainly got the fortune in this game, with a contentious refereeing decision and Brill's gift to Doolan shortly before the end.
Second-placed Inverness will have felt aggrieved to have the lost the match with Celtic dropping points on Saturday.
However, on the evidence of the opening period, they might have thought their home record would be safe as they took the game to the visitors.

Doran came close with a free-kick before Ben Greenhalgh, starting his first game and eager to impress, had an effort cannon off the post.
However, it was Doolan, having received a James Craigen cutback, who showed the coolness and composure to fizz a shot past Brill to give the Jags the lead.
Partick were quite content to let Inverness have possession, but Archibald's men threatened on the counter on several occasions.
Craigen had time and space on the edge of the box and attempted to curl a shot towards goal, but he failed to find the target.
Stephen O'Donnell was next to try his luck as they flooded forward once more, but his effort was also wayward.
The game's big talking point arose just before half-time when Inverness thought they had found an equaliser.
A training-ground corner led to Doran dinking the ball across to Billy McKay, whose effort was cleared off the line before Doran rifled past a flurry of defenders and Scott Fox in goal.
However, referee Euan Norris disallowed the strike and brought play back, insisting that Ross Draper's initial touch at the corner flag had not restarted play, much to the fury of the Inverness players.
Their feeling of injustice spurred them on, though, and it was not long before they found an equaliser shortly after the break when Warren powered a header beyond Fox.
It seemed as though Inverness were starting to assert their authority on the game as Partick were struggling to deal with the aerial power they posed.
They looked vulnerable when Richie Foran rose above Isaac Osbourne to head into the net, but the official blew his whistle for an infringement.
Inverness spurned more chances through Draper and Foran as they looked to keep their 100% home record intact.
However, it was a howler from Brill that gave Doolan the simplest of chances to knock the ball in from a yard and give Partick the three points.
Line-ups
Inverness CT
Formation 4-4-1-1
- 12Brill
- 2Raven
- 3Shinnie
- 8Draper
- 5WarrenBooked at 63mins
- 6Meekings
- 10Doran
- 9ForanBooked at 44mins
- 7MckaySubstituted forAgdesteinat 90+1'minutes
- 11RossSubstituted forPolworthat 69'minutes
- 17GreenhalghSubstituted forWatkinsat 71'minutes
Substitutes
- 1Esson
- 14Devine
- 15Watkins
- 18Tremarco
- 19Williams
- 20Polworth
- 23Agdestein
Partick Thistle
Formation 4-2-3-1
- 1Fox
- 2O'Donnell
- 3Sinclair
- 19OsbourneBooked at 13mins
- 5MuirheadBooked at 3mins
- 6Balatoni
- 7CraigenSubstituted forElliottat 73'minutes
- 4Welsh
- 9Doolan
- 8BanniganBooked at 90mins
- 23HigginbothamBooked at 43minsSubstituted forLawlessat 82'minutes
Substitutes
- 10Forbes
- 11Lawless
- 12Gallacher
- 13Rojo de la Vega
- 14Elliott
- 17Baird
- 22Fraser
- Referee:
- Euan Norris
- Attendance:
- 3,154
Match Stats
- Possession
- Home51%
- Away49%
- Shots
- Home14
- Away9
- Shots on Target
- Home4
- Away2
- Corners
- Home12
- Away2
- Fouls
- Home14
- Away15
Live Text
Post update
Full Time
Second Half ends, Inverness CT 1, Partick Thistle 2.
Post update
Attempt missed. Richie Foran (Inverness CT) header from the centre of the box is too high.
Post update
Corner, Inverness CT. Conceded by Aaron Sinclair.
Post update
Corner, Inverness CT. Conceded by Aaron Sinclair.
Post update
Attempt blocked. Torbjorn Agdestein (Inverness CT) right footed shot from the right side of the box is blocked.
Booking
Stuart Bannigan (Partick Thistle) is shown the yellow card.
Post update
Marley Watkins (Inverness CT) wins a free kick in the attacking half.
Post update
Foul by Stuart Bannigan (Partick Thistle).
Substitution
Substitution, Inverness CT. Torbjorn Agdestein replaces Billy McKay.
Post update
Corner, Inverness CT. Conceded by Isaac Osbourne.
Post update
Attempt blocked. Marley Watkins (Inverness CT) right footed shot from the centre of the box is blocked.
Post update
Billy McKay (Inverness CT) wins a free kick in the attacking half.
Post update
Foul by Conrad Balatoni (Partick Thistle).
Post update
Corner, Inverness CT. Conceded by Aaron Sinclair.
Post update
Corner, Inverness CT. Conceded by Stephen O'Donnell.
Goal!
Goal! Inverness CT 1, Partick Thistle 2. Kris Doolan (Partick Thistle) left footed shot from very close range to the top left corner.
Substitution
Substitution, Partick Thistle. Steven Lawless replaces Kallum Higginbotham.
Post update
Corner, Partick Thistle. Conceded by Graeme Shinnie.
Post update
Attempt missed. Richie Foran (Inverness CT) right footed shot from outside the box misses to the right.