Edinson Cavani scored a superb late goal to deny Ajaccio a famous win at the Parc des Princes as Paris St Germain were held to a home draw by the Corsicans.
Despite dominating from start to finish Laurent Blanc's champions were left frustrated not to get a win after Benoit Pedretti had given the visitors an early lead with a wonder goal.
A draw for PSG leaves them winless after two games and already four points off the leading pack while Ajaccio gained their first point of the season.
Much to the surprise of almost everyone at the Parc des Princes it was the visitors who took the lead inside the opening 10 minutes with their only chance of the game.
Sigamary Diarra saw his cross blocked but the ball eventually fell at the feet of Pedretti who bent a superb shot into the top corner from 20 yards to leave Salvatore Sirigu with no chance.
The Parisiens responded and went close to an equaliser just after the half-hour mark when Javier Pastore picked out Zlatan Ibrahimovic but, after bringing the ball down brilliantly, the big Swede dragged his effort just wide of the left post in what was the hosts best chance of the first half.
Despite Cavani forcing a save from Guillermo Ochoa with a near-post header and Ibrahimovic also nodding just wide, Fabrizio Ravanelli's men held out to go into the break with an unlikely lead having been dominated throughout.
The PSG onslaught continued after the restart and Cavani almost equalised when his bullet header was met by a fantastic two-handed diving save by Ochoa as the hosts continued to press for the equaliser.
Ochoa was called into action again when he showed great reflexes to keep out Thiago Silva's point-blank header before Blaise Matuidi and youngster Joshua Nadeau were both carried off following a sickening clash of heads inside the Ajaccio penalty area.
With the clock counting down, Ajaccio's Mexican goalkeeper continued to hold PSG at bay single-handedly when he raced off his line to bravely deny Ibrahimovic as Blanc's men began to get frustrated.
PSG's Thiago Silva was next to go close when he thumped a well-timed header against the crossbar before Cavani stole the headlines late on with his first PSG goal on his home debut.
Substitute Hervin Ongenda picked out the Uruguayan 20 yards out and he shifted the ball onto his trusted left foot before thundering a shot into the top corner.
There was still time for the inspirational Thiago Silva to find the crossbar again with a thundering shot from 18 yards but PSG failed to find the crucial goal that would seal all three points.