Second-half substitute Blaise Matuidi struck with just over a minute of normal time remaining as Paris Saint-Germain moved to within one win of securing the Ligue 1 title with victory over 10-man Evian TG.
It was visitors Evian who surprisingly started better, with Daniel Wass striking the bar with a free kick in the fifth minute before Nicolas Benezet's effort was kept out by Salvatore Sirigu.
Wass then went close again when his header was saved by Sirigu.
PSG began to dominate after 20 minutes but they couldn't find the net as Ezequiel Lavezzi, Javier Pastore and Yohan Cabaye all squandered opportunities before the break.
The match swung heavily in PSG's favour when Evian right-back Kassim Abdallah picked up two bookings in eight minutes to be sent off.
Laurent Blanc's side kept knocking at the door and eventually they found a way through when Matuidi fired low across goal into the bottom corner.
Three points puts PSG 10 points clear of second-placed Monaco with four games of the season remaining. Evian remain five clear of the drop zone.