Rod Fanni scored late at the Stade Velodrome on Saturday to help Marseille move into second place in Ligue 1 with a 1-0 defeat of Valenciennes.
The two sides appeared to be heading for a scoreless draw until the fourth minute of stoppage time when Fanni rose above his mark to head home a corner kick delivered by Jeremy Morel.
Fanni's second goal of the season sees Marseille improve to 46 points on the season, five points shy of first-place PSG and one point clear of third-place Lyon.
The result places added pressure on PSG and Lyon to pick up maximum points from their respective matches on Sunday as they take on Sochaux and Bordeaux, respectively.
Valenciennes has dropped three of its last four league games to remain on 33 points for the season.
Toulouse and Troyes played to a dramatic 2-2 draw at the Stade Municipal de Toulouse on Saturday.
Troyes thought it had claimed the win when Mohamed Yattara and Benjamin Nivet scored in the 78th and 83rd minutes, but Toulouse earned a share of the spoils thanks to 87th-minute and 88th-minute goals from Eden Ben Basat and Etienne Didot, respectively. Troyes has drawn three straight league games to remain second from bottom with 19 points while Toulouse improves to 32 points.
Elsewhere in Ligue 1 on Saturday, Emanuel Herrera scored the lone goal in Montpellier's 1-0 defeat of Nancy, Jeremie Aliadiere and Kevin Monnet-Paquet scored a goal apiece to help Lorient earn a 2-1 win over Evian, Neal Maupay's goal at the hour mark saw Nice claim a 1-0 victory at Bastia and Florian Raspentino exchanged goals with Dennis Oliech as Brest played to a 1-1 draw with Ajaccio.