Radamel Falcao marked his first start in six weeks with the only goal of the game as Monaco cemented their position at the top of Ligue 1 with a 1-0 win at Angers.
Falcao's goal came just after the hour mark and against the run of play, and Monaco were holding on at the end against in-form opponents at the Stade Raymond Kopa.
The result extended the principality side's run without defeat in the league to 13 matches and moved them four points clear at the top of the table with a game in hand on Nice, who won 2-1 at Lille on Friday.
Defending champions Paris Saint-Germain -- who hammered Monaco 4-1 in last weekend's League Cup final -- can cut their lead back down to three points if they win at home to Guingamp on Sunday evening.
For Monaco it was the perfect preparation for their Champions League quarter-final first leg away to Borussia Dortmund in Germany on Tuesday as they stay on course to win their first French title since Claude Puel's 2000 vintage.
"It is always difficult to play away from home in the French league and more so in Angers. It is not by chance that we lost 3-0 here last year," said Monaco coach Leonardo Jardim.
"We made some changes to the team, brought in tougher players, players who are better in the air, a bit more aggressive, so that we could go to war."
This always looked likely to be an awkward trip for Monaco against their fellow French Cup semi-finalists, with Angers a big, strong and physical side who had been unbeaten at home since December.
Jardim named Falcao in his starting line-up for the first time since late February with the Colombian looking to prove his fitness before the Dortmund clash.
Teen sensation Kylian Mbappe made way but Falcao and Monaco offered little going forward in the first half and were lucky not to be behind at the interval.
Cameroon forward Karl Toko Ekambi pounced on a loose ball just outside the Monaco box only to fire wide, while goalkeeper Danijel Subasic made a crucial intervention in front of Famara Diedhiou.
The goal arrived in the 61st minute, Nabil Dirar setting up Falcao for a low right-foot finish from 12 yards for his 17th of the season in the league and his 25th altogether.
Angers did not deserve to find themselves behind but they passed up a glorious chance to level late on when Ismael Traore turned the ball against the far post following a Thomas Mangani free-kick. Subasic prevented Diedhiou from scoring the follow-up.
"There is no team in the Champions League that plays like that," added Jardim looking ahead to the Dortmund trip.
"Against Dortmund the problem will not be possession, it will be having only two days to recover before we play in an international competition."
- Lyon humbled -
Later, any slim hope Lyon had of snatching a top-three finish evaporated as they slumped to a 4-1 defeat at home to struggling Lorient.
Corentin Tolisso put Lyon in front but Majeed Waris equalised before the break and Sylvain Marveaux put Lorient ahead early in the second half.
Benjamin Moukandjo, Cameroon's Africa Cup of Nations winning captain, then netted twice as Lorient claimed a third successive victory to climb out of the bottom two for the first time since the start of October.
Bordeaux moved back up to fifth and to within five points of Lyon in fourth with a 3-0 win against Metz.
Brazilian starlet Malcom opened the scoring and Argentinian midfielder Valentin Vada struck a second-half brace, the first a penalty.
Bastia kept alive their survival hopes with a 2-1 win at Dijon, who join the Corsicans in the bottom two.
Issiar Dia netted twice as Nancy, another relegation threatened side, beat Rennes 3-0 while Montpellier won 2-0 at Caen.