It was a trying evening in Corsica for the big-spending capital club, who were held scoreless by the pugnacious hosts, leaving them with only two points from as many matches
The visitors started the match without high-profile summer signings Zlatan Ibrahimovic and Thiago Silva - and had both winger Ezequiel Lavezzi and coach Carlo Ancelotti dismissed during the second half.
PSG offered little offensively over the course of the game, although Jeremy Menez should have scored from close range in the first half, and it was the visitors who actually came closest to winning the match, with Eduardo striking the post.
Even at the outset of the match, it was Ajaccio who showed the greater energy and verve on a hot Corsican evening. Ricardo Faty’s cross from the right was turned on by Johan Cavalli to the free Sigamary Diarra, but the winger, who was unmarked at the back post, failed to control the ball sufficiently to threaten Salvatore Sirigu properly.
For all the hosts’ early energy, they were largely limited going forwards and the Italian would be infrequently tested. Eduardo did make the occasional dangerous incursion but as the half wore on, PSG’s influence increased.
Javier Pastore had a quiet match, yet it was his searching pass that unlocked the home rearguard. Nene gathered the ball on the left wing before squaring for Menez, whose effort from inside the six-yard box was superbly blocked by Guillermo Ochoa.
Before the interval, Nene would twice threaten from free kicks. His first was a direct effort on goal that flew just over, while the second was a cross that ultimately ended with Clement Chantome tamely heading at Ochoa.
These efforts were rather isolated bright spots for PSG in the opening period and after the interval they were equally well restricted by the rugged and determined hosts. The frustration the visitors were feeling became clear when Lavezzi rashly challenged Bejamin Andre and was deservedly shown a red card for a two-footed stamp on the midfielder.
By this point, Eduardo had already pounced on a loose Mamadou Sakho pass to hit the post, heightening the pressure on the guests.
With around 10 minutes remaining, Ancelotti would be dismissed from the dugout, having kicked out at a water bottle in a show of pique.
Ajaccio would not commit too many players forward, aware that a point was not a bad result against a powerful outfit, and opportunities in the closing stages of the match were rare. Their attacks were largely measured, but while adopting a more offensive stance, they were sure to keep things tight at the back.
Deep into stoppage time, the drama was added to as the floodlights failed, but there was no time once play restarted for either team to fashion an opening.
While the hosts settled happily for a draw, preserving their unbeaten home record in 2012, PSG have now failed to win either of their opening two matches and come under significant pressure heading into difficult matches against Bordeaux and Lille.