Radamel Falcao fired Monaco's Ligue 1 title push in a tense 1-0 victory at Angers.
Falcao was restored to the Monaco starting line-up for the first time since the end of February after a hip injury.
And the league leaders were grateful for the striker's return as his 61st-minute winner -- his 17th goal in Ligue 1 this season -- saw them extend their advantage over second-placed Nice to four points.
Paris Saint-Germain could cut Monaco's lead to three points when they entertain Guingamp on Sunday night, but Leonardo Jardim's side remain in the title driving seat.
Jardim felt Falcao needed game-time ahead of Tuesday's Champions League clash against Borussia Dortmund and the Colombian looked slightly rusty until his second-half strike.
But Falcao was also short on service as Angers, who had won five of their previous seven games, dominated the first period and Monaco were grateful that their Croatian goalkeeper Danijel Subasic was in fine form.
Bernardo Silva almost fashioned an early chance for Valere Germain, but Subasic was soon called into action to stop Karl Toko Ekambi and Famara Diedhiou from opening the scoring.
Toko Ekambi was a constant nuisance to the Monaco defence, and the Cameroon striker shot into the side-netting before his 25th-minute free-kick was held at the second attempt by Subasic.
But Toko Ekambi was unable to accept a gilt-edged chance following a defensive mix-up between Kamil Glik and Almamy Toure.
Subasic came to Monaco's rescue again after 38 minutes when Cheikh N'Doye slipped Diedhiou through and he stopped the Senegalese striker taking the ball around him.
The danger for Angers was that Monaco had to improve after such a sluggish first half.
And the first signs of that was when Benjamin Mendy's free kick landed at the feet of Tiemoue Bakayoko in the penalty area only for the midfielder to slot wide of the upright.
But Monaco did not have to wait long for the breakthrough as Nabil Dirar delivered a delightful pass into the path of Falcao, who found the back of the net.
N'Doye's header almost beat Subasic before Angers goalkeeper Alexandre Letellier, playing his first league match of the season after rupturing cruciate ligaments in August, produced an amazing treble save to deny Toure, Germain and Glik.
Monaco held on to take a precious three points -- their 23rd league win of the season -- although there was a late scare when Jonathan Bamba's header struck a post six minutes from time.