Benjamin Nivet's 88th-minute goal stunned Ligue 1 giants Marseille as struggling Troyes picked up their first win of the season to keep L'OM off the top of the table.
Troyes withstood heavy pressure throughout the game and then, having earlier hit the crossbar with a rare second-half attack, Nivet prodded home a loose ball to snatch all three points.
It was the ultimate smash-and-grab raid, with Nivet lucky to get away with after appearing to use an elbow only seconds before the goal and Marseille then denied a 90th-minute leveller by an assistant's flag.
The win lifted Troyes off the foot of the table, while Marseille remained second, behind Paris St Germain on goal difference.
According to the stats, this should have been a one-sided Marseille victory, and the visitors set out trying to make it so as they bombarded the Troyes goal.
Benoit Cheyrou gave home goalkeeper Yohann Thuram-Ulien an early touch with a third-minute free-kick that was on target, and Thuram-Ulien was on hand again to keep out a first-time shot from Morgan Amalfitano.
However, Marseille suffered a big blow when Andre-Pierre Gignac went off injured, scans later revealing he had broken a bone in his foot.
The visitors continued to pour forward, though, and Amalfitano turned provider for Gignac's replacement Loic Remy, but the striker could not find the target with his 28th-minute shot.
The onslaught continued early in the second half, with Thuram-Ulien pushing Mathieu Valbuena's free-kick away for a corner shortly after the restart.
Troyes went close with their first serious chance in the 55th minute as Nivet met Stephane Darbion's corner and headed on to the bar with Steve Mandanda beaten.
Marseille almost came up with the perfect response, but somehow Remy headed down and over when all alone at the far post from Andre Ayew's cross.
Remy's penalty shout for a challenge by Matthieu Saunier was turned down as the game moved into the last 10 minutes and Marseille got increasingly desperate.
Thuram-Ulien only saw Charles Kabore's half-volley late, but made the save and it seemed the away side's luck was out.
That impression was only strengthened when Nivet got away with a booking when he appeared to use an elbow.
And seconds after that escape he fired in the winner, pouncing on the rebound when Mandanda could only parry Marcos' header.
Marseille thought they had a dramatic late equaliser, but Remy's effort was rightly ruled out for offside.