Marseille picked up a 1-0 win over Lille at the Stade Velodrome, which sees them join PSG on 26 points at the top of Ligue 1 and leapfrog both Lyon and Bordeaux.
Jordan Ayew's second-half header from Mathieu Valbuena's cross proved enough with OM goalkeeper Steve Mandanda doing well to keep out efforts from Nolan Roux.
Following the goal, things got easier for Elie Baup's men as Florent Balmont saw red for a dangerous tackle on Valbuena.
Earlier, Lyon's annual capitulation at the Stadium Municipal saw Wissam Ben Yedder bag a brace as Toulouse climbed up to seventh with a 3-0 win.
Ben Yedder's double and Etienne Capoue's last-minute strike goal made it 11 goals conceded without reply from Lyon's last seven trips to the south west, as Remi Garde's men missed the opportunity to dislodge Paris St Germain from the top of the table.
Bordeaux also missed the chance to move to the top of the table as Remy Cabella's goal midway through the second half gave struggling champions Montpellier a 1-0 victory.
The hosts started the game level with Sochaux, who occupied the third relegation spot - but Cabella's goal was just reward for their second-half display and gave them only a fourth win in 14 games, lifting them five places to 12th.
Information from the Press Association was used in this report