Just as had been the case at Strasbourg last weekend, the Parisian giants looked to be cruising to victory but then let their opponents back into the game and had to share the spoils.
It was third successive draw for PSG, who secured the Ligue 1 title a fortnight ago, and a precious point for Troyes, now six points clear of the relegation places with two games left to play in this campaign.
Kylian Mbappe was brought down in the opposing penalty area to allow Neymar to double the score with a 25th minute spot kick, but the advantage was reduced five minutes later when Nuno Mendes' errant pass back into the heart of the PSG defence fell for Troyes' London-born striker Ike Ugbo, who wasted no time crashing home a powerful shot.
Troyes then levelled four minutes into the second half after Renaud Ripart was wrestled to the ground by PSG's France international centre-back Presnel Kimpembe and the visiting captain Florian Tardieu smartly converted the resultant spot kick.
PSG pushed for the win as Neymar had an effort chalked off by VAR after Mbappe was found to have pushed off a defender in the build-up and Marquinhos was only inches away from a second goal as he put an 84th minute header wide.
In stoppage time at the end of the game, Lionel Messi struck the woodwork as Troyes grimly hung on for a potentially precious point.