Wissam Ben Yedder scored with a superb finish as Monaco won 1-0 at Angers to put pressure on French title rivals Lyon and Lille ahead of their match later on Sunday.
The France striker latched onto a pass from midfield and expertly dinked the ball over onrushing goalkeeper Paul Bernardoni in the 79th minute for his 18th league goal of the season.
"It's good that we won this game, it was difficult," Ben Yedder said. "We know we're in the final sprint now. Some people are saying we will finish as champions, but we'll take what we can. Every match will be hard."
Forward Stevan Jovetic had an early chance saved by Bernardoni and then limped off injured after 16 minutes. He was replaced by Ben Yedder, who is being cleverly used as a substitute in recent game s by coach Niko Kovac, regardless of his status.
"Whether I start the game or not, the important thing is to play collectively and help the team out," Ben Yedder said.
Monaco has lost only once in 23 games overall and moved provisionally into second place. Lille had to win at fourth-place Lyon to move back to the top by one point ahead of PSG, which won 3-1 at Metz on Saturday.
Rennes has been transformed under new coach Bruno Genesio and beat last-place Dijon 5-1 at home for a fifth win in six games since he took charge.
The defeat relegated Dijon but seventh-place Rennes maintained its drive for fifth and a Europa League spot next season.
But Lens holds that place and is two points ahead of Rennes after winning 2-1 at home to 19th-place Nimes.
Nantes moved over Nimes and into 18th position with a 2-1 win at Strasbourg.
The day after around 1,000 protesting fans called for a leadership change at the financially troubled club, the players collapsed on the field in a 4-1 defeat at Lorient.
By halftime it was 3-0.
Lorient's strike partnership of Terem Moffi and Yoane Wissa tore apart the defense, with Moffi netting twice after Wissa opened the scoring.
Moffi completed his hat trick, taking the 21-year-old Nigerian's league tally to 14.
Bordeaux is in 16th place, one spot above Lorient, with both aiming to stay clear of 18th and the promotion-relegation playoff.
Montpellier's 15-game unbeaten league and French Cup run came to an end with a 3-1 defeat at Nice.
Eighth-place Montpellier hit the crossbar after 37 seconds and took the lead in the second minute when Andy Delort set up strike partner Gaetan Laborde to head home.
A frantic start saw Nice equalize three minutes later when striker Kasper Dolberg set up midfielder Hicham Boudaoui.
Poor defending allowed Nice to score twice close to halftime through defender Jean-Clair Todibo and midfielder Alexis Claude-Maurice.
