Perpignan suffered a 23rd loss in 25 Top 14 games as Louis Dupichot and Simon Zebo scored hat-tricks in Racing 92's 52-14 victory.
Paddy Jackson will leave Perpignan after a single campaign in France, joining London Irish for their return to the Premiership.
Grenoble look to be heading for a relegation play-off after losing at home to their nearest rivals Agen.
La Rochelle put Pau to the sword and Castres also enhanced their chances of reaching the play-offs with a win in Bordeaux.
Toulon may have been at a numerical disadvantage for most of the second half but they still managed to defeat Top 14 leaders Toulouse.
Tries from Carl Fearns, Mickael Ivaldi and Thibaut Regard helped Lyon get back to winning ways in Saturday's Top 14 action.
There were big wins for 2017-18 Top 14 finalists Castres and Montpellier on Saturday, with Benjamin Urdapilleta inspiring.
A 28-9 victory over Stade Francais saw Top 14 leaders Toulouse break a league record as they extended their unbeaten run to 12 games.
Zack Holmes scored 15 points as Toulouse extended their lead at the Top 14 summit, while Stade Francais boosted their play-off hopes.
Perpignan finally had a win to celebrate, while Clermont Auvergne were too good for Bordeaux-Begles in Top14.
For the second time in two days, a side racked up a century of points in the Challenge Cup as Bristol Bears routed Enisei... Read more
Zebre led at half-time of their European Challenge Cup match at La Rochelle, but the hosts fought back in stunning fashion on Friday.
Racing 92's win over Toulon will not have made pleasant viewing for France coach Jacques Brunel as Teddy Thomas was injured.
The battle between top and bottom in the Top 14 table stayed true to form, Clermont running out comfortable winners on the road.
Stade Francais moved up to fifth in the table as Toulon and Racing 92 ran out convincing winners in Saturday's Top 14 action.
Tributes were paid to teenager Nicolas Chauvin before and after Stade Francais got the better of the Ospreys in Paris.