Victory over Stade Francais moved Racing 92 to within four points of Top 14 leaders Montpellier but Toulon slipped to defeat at Oyonnax.
Stade Francais' five-match losing run in the Top 14 came to an end on Sunday, while Toulouse missed the chance to take second.
The leaders of the Top 14, Montpellier, thumped their nearest rivals on Saturday, while struggling Oyonnax also claimed an important win.
Defeat to Racing 92 would have seen Montpellier deposed as Top 14 leaders, but Vern Cotter's men made a statement with a bonus-point win.
Ben Botica ensured Oyonnax built on their win at Clermont with another victory that boosted their unlikely Top14 survival bid.
Montpellier's lead at the summit was cut to three points after they went down at Agen and Racing 92 defeated struggling Brive.
Former France fly-half Yann Delaigue says young players are not being given a chance to develop in the Top 14.
Simon Shaw said he would not make himself unavailable to play for England at Danny Cipriani's age, but can understand why he might.
La Rochelle are a formidable force on home soil, but suffered a rare defeat at Stade Marcel-Deflandre as Toulon came from behind to win.
Agen and Oyonnax secured rare wins at the foot of Top 14, while Montpellier enjoyed another successful day at the top.