Top 14 leaders Toulouse moved seven points clear with a 23-19 victory at La Rochelle and 14-man Racing 92 beat Bordeaux-Begles in a high-scoring contest on Sunday.
Toulouse extending their winning run to seven matches after being pushed all the way by top-six contenders La Rochelle at Stade Marcel-Deflandre.
It is now 14 matches without defeat for a Toulouse side that had a slender 10-9 lead at the end of a first half which saw just the one try from Lucas Tauzin.
Thomas Ramos was on target with his second penalty of the evening early in the second half, but Ihaia West responded with his fourth successful strike from the tee in a tight affair.
Piula Faasalele went over to extend Toulouse's advantage just before the hour-mark, yet La Rochelle continued to pose a threat and Vincent Rattez scored their only try just a few minutes later.
West converted to reduce the gap to a point as La Rochelle scented a big victory, but Ramos sent the ball sailing through the posts again nine minutes from time as Toulouse saw out yet another win.
Racing moved four points clear of Bordeaux with an entertaining 45-27 win at La Defense Arena.
Irish duo Donnacha Ryan and Simon Zebo were among the six Racing try-scorers in an encounter which saw Teddy Iribaren red-carded 11 minutes from time for striking Baptiste Serin.