Monaco beat slumping Marseille 3-0 on Saturday to take second place in Ligue 1 from their opponents and boost their hopes of qualifying for next season's Champions League.
The principality club lead Marseille by one point with five matches remaining, but seventh-placed Nice are only five points further adrift with a game in hand.
Monaco inflicted a fourth defeat in five Ligue 1 games on Roberto De Zerbi's Marseille, who are in danger of throwing away a Champions League place after sitting second in the French top flight for much of the campaign.
"We have to remain cautious because the gap is only one point," said Monaco coach Adi Huetter. "It will be very close with our opponents."
The teams who finish second and third behind champions Paris Saint-Germain will secure spots directly into the Champions League, with the fourth-placed side heading into the qualifying rounds.
"We're still alive, we still have a great chance of reaching the Champions League," said Marseille coach De Zerbi.
"I have nothing to say to the players; we must remain united. I'm optimistic. I'm more optimistic tonight than after some defeats and even some victories."
Monaco took the lead in the 34th minute at the Stade Louis II when Takumi Minamino swept home his fifth league goal of the season following some dreadful Marseille defending.
OM came close to an equaliser shortly before half-time, but Luis Henrique's effort was well saved by Monaco goalkeeper Philipp Kohn.
The hosts doubled their advantage shortly before the hour as Breel Embolo slipped the ball past Geronimo Rulli after an excellent pass through from Vanderson.
The goal was awarded following a lengthy VAR review for offside.
Monaco added further gloss to the scoreline and bolstered their goal difference, which could prove crucial, through Denis Zakaria's late penalty.
"In the first half, we played very well, even if we didn't have any great chances apart from Luis Henrique's," added De Zerbi.
"But we didn't suffer too much, and I find it difficult to explain their goal. It was a stupid goal, and that happens to us too often."
Lille climbed to fourth with a 2-1 victory at Toulouse, although either Strasbourg or Nice could overtake when they meet later on Saturday.
Mitchel Bakker scored the winning goal in first-half injury time, after Toulouse centre-back Charlie Cresswell had cancelled out Mathias Fernandez-Pardo's opener.
jc/pb
