Chu Young-Park was the match-winner for Monaco as they held on for almost 70 minutes to beat Ligue 1 rivals Rennes at the Stade Louis II.
Park powered home from close range after 21 minutes to break the deadlock and, although both sides had a number of chances, there was no further scoring.
As well as three vital points, the win also provided a timely morale-boosting clean sheet following their 4-0 humbling at the same stadium against Lille at the weekend.
It was Rennes who started strongest, Jerome Leroy breaking into space in the fourth minute and sending a powerful shot just over the crossbar.
Jires Kembo-Ekoko was next to take aim at the Monaco goal, forcing Stephane Ruffier into a smart save at the near post inside 10 minutes.
Despite that bright beginning, the home side drew first - and is turned out, only - blood when Nene located Sebastien Puygrenier with his free-kick from the left flank.
Puygrenier cleverly nodded the ball on to Park at the far post and the Korean forward prodded home from point-blank range.
The pace slowed thereafter until a late flurry of action just before half-time, with Alejandro Alonso, for Monaco, and Kembo-Ekoko, for the visitors, both missing with good chances.
With 57 minutes gone Nene had the chance to make it 2-0 to the home side after being played in by the inventive Puygrenier. While his shot had plenty of power it missed the target by inches.
Rennes dominated the play until the final whistle, striving in vain for an equaliser, but despite their possession they lacked the end product.
Ismael Bangoura, Leroy and Sylvain Marveaux all had chances but none could beat Ruffier.
