Brest moved a little closer to Paris Saint-Germain with a 1-0 home win over Le Havre on Sunday, as Nice missed the chance to go third in Ligue 1 with hosts Toulouse coming from a goal down to win.
A goal just after the half-hour from Pierre Lees-Melou gave Brest victory to close the gap to PSG to nine points and seal a club record 13 top-flight matches without defeat.
"Very satisfied. We've got a bit of a lead on points, it's good to get them now," said Brest coach Eric Roy.
"I'm proud and happy for our team, who have made history by going 13 games unbeaten."
The win gives Brest a four-point cushion over third-placed Monaco, who played out a goalless draw with PSG on Friday.
Midfielder Lees-Melou slotted in Mathias Pereira Lage's cross at the near post with 34 minutes on the clock in what was the decisive moment of a close-fought match.
Brest held firm in the second half to close out the three points as fatigue set in for both sides and the foul count rose.
Nice miss out
Nice failed to hold onto a first-half lead and break back into the top three after going down 2-1 at Toulouse.
Terem Moffi gave Nice the early advantage when he fired past Guillaume Restes after eight minutes.
Affairs were levelled in the 65th minute when Warren Kamanzi crossed for Thijs Dallinga to head his ninth goal of the season and his fourth in the last five matches.
Four minutes later, the Dutch striker teed the ball up for Yann Gboho who swivelled round Pablo Rosario before crashing the ball past Nice goalkeeper Marcin Bulka.
Nice remain in fifth, missing the chance to go above Monaco and Lille.
"We need to wake up," said Nice coach Francesco Farioli, after his team failed to win for a fifth consecutive league match.
"We're still fifth, so we're still in a position to achieve our goals. We need to rediscover the energy we had at the start of the season."
For Toulouse, the win moved them up a place to tenth, leap-frogging Lyon who lost 3-0 at home to Lens in Sunday's late match.
Florian Sotoca broke the deadlock with a predatory header just before half-time and then second-half goals from Elye Wahi and Kevin Danso sent Lens above Marseille into sixth place.
The first goal came at the end of a half that was edged by the visitors but in which Lyon looked dangerous on the counter with the pace of Ernest Nuamah, who rattled the post inside the opening 15 minutes.
Skilful wing play on 43 minutes by David Pereira Da Costa was finished off by Sotoca who had ghosted in at the back post for a free header.
Six minutes into the second half, VAR spotted a handball against Lyon captain Maxence Caqueret and Wahi dispatched the resulting spot-kick to put Lens in control.
Lyon finished a man down after Ainsley Maitland-Niles was given a red card for a professional foul. Moments later Danso headed in the third from a corner in the 87th minute.
Lowly Metz picked up three points with a 2-0 win at Nantes, courtesy of two second-half goals in two minutes from Georges Mikautadze, from the spot, and Matthieu Udol.
Lorient escaped the relegation play-off spot by downing Breton rivals Rennes 2-1 thanks to Mohamed Bamba and an Eli Kroupi strike on 90 minutes, before Amine Gouiri struck back for the hosts deep in injury time.
Montpellier came from behind twice to draw 2-2 with visiting Strasbourg. A brace from Arnaud Nordin cancelled out Mouhamadou Diarra's penalty and an Emanuel Emegha goal.
The results mean Montpellier dropped to 16th after Lorient's win and only have a three-point buffer between themselves and Metz in the automatic relegation zone.
