A depleted Toulon team came a cropper at Castres, allowing Clermont Auvergne to take over as new leaders in the Top 14.
The final of the Top 14 will be held at Barcelona’s Nou Camp at the end of the 2015-16 season.
Oyannax caused the biggest upset of the Top 14 season so far on Saturday by clinching victory away at Racing Metro.
Saturday sees four European Rugby Challenge Cup showdowns, with Cardiff, Exeter, Connacht and Gloucester all in action.
Cardiff Blues kicked off their European Rugby Challenge Cup campaign with a 37-14 bonus-point victory over Grenoble.
There are seven European Rugby Challenge Cup matches across Saturday and Sunday. Sky Sports previews them all.
Sky announces the European rugby fixtures being brought to your screens in December.
Clermont sit on top of the Top 14 table as they became the first visiting team to taste victory at Oyonnax this season.
Clermont returned to the summit of the Top 14 standings in style while Castres climbed out of the relegation zone.
Toulon were beaten at home by Stade Francais, while Racing Metro, Bayonne and Oyonnax all earned victories.
Champions Toulon, Brive, Clermont, Lyon, Grenoble and Stade Francais were all winners in the Top 14 on Saturday.
Alipate Ratini scored a magnificent hat-trick to lead Grenoble to a first win of the season, 37-23 over Bordeaux-Bègles.
Montpellier produced a stirring fightback against Grenoble to get their season back on track.
Toby Flood made a memorable Top 14 debut for Toulouse, scoring all their points in a 20-19 victory over Oyonnax.
Sky Sports brings you all you need to know about French rugby and the 2014-15 Top 14 season.
Sky Sports kicks off its European Rugby Champions Cup coverage with the top teams from across the continent.
South Africa have released five players to their French clubs for Top 14 duty this weekend.
Former England winger Paul Sackey has signed for Harlequins on a three-year deal.
Worcester Warriors have confirmed the signing of French prop Jeremy Becasseau from Stade Francais.
Sale and Worcester have been drawn in the same pool for next season's Amlin Challenge Cup.
Stuart Lancaster's side bid to extend winning run against Australia