Toulon shrugged off the absence of injured South African star Cheslin Kolbe to beat champions Toulouse 19-15 and boost their push for a Top 14 play-off spot on Saturday.
World Cup winger Kolbe will be sidelined for several weeks with a broken thumb.
It was fellow winger and French international Gabin Villiere who grabbed the headlines at a sold-out Stade Velodrome in Marseille with the only try of the match nine minutes from time after beating four defenders.
Toulouse, without their Six Nations half-back stars Antoine Dupont and Romain Ntamack, scored all their points courtesy of the boot of Thomas Ramos.
The win pushed Toulon into eighth place in the table, three points behind Toulouse in race for the play-offs.
Racing92 ran in five tries to defeat Biarritz 40-7 to go fifth.
Two of the tries came from international winger Teddy Thomas who said he wants to deliver the Top 14 title to the Paris club before moving to La Rochelle in the summer.
"I've been here for eight years but unfortunately, I didn't win a title," he said.
"There are a lot of players leaving Racing. We are all committed to winning something, whether it's the European Cup or the Top 14. We give 200 percent to be able to leave this club with our heads held high and make it proud."
Castres boosted their hopes of a place in the play-offs with a grinding 12-0 win at home to Clermont.
In filthy conditions with driving rain, Castres, who have yet to lose at home this season, were unable to cross the paint, but four penalties from Argentinian fly-half Benjamin Urdapilleta -- two in each half -- were enough to secure the victory.
"We played the game we needed given the weather conditions," said Urdapilleta.
"We played well tactically. We have an intelligent group, we know how to play this kind of match."
The key moment came at the end of the first half when Clermont were camped in Castres territory and seemed certain to score.
"When I saw how our forwards defended, I wanted to cry," said Urdapilleta.
"To see their commitment, how they managed to hold on... when you see that, it makes you want to fight."
Stade Francais, down in 11th, won 21-18 at home against Pau.
After tries from Adrien Lepegue, Lester Etien, Pierre-Henri Azagoh, the Parisians led 18-6 and were on course for an offensive bonus but Pau hit back with two late tries from fly-half Antoine Hastoy to level at 18-18.
A late penalty from Nicolas Sanchez clinched the win for Stade who moved one point behind Pau who collected a bonus point, and four behind eighth-placed Clermont.
Sunday sees a top of the table clash between Montpellier and Bordeaux-Begles.