Lyon surrendered first place in Top 14 as they lost away to Bordeaux-Begles, who won a contest that was closer than the scoreline suggests.
Top 14 front-runners Lyon won again, while La Rochelle's Arthur Retiere grabbed a hat-trick and Brive left it late.
Northampton Saints and Glasgow Warriors did all they could to stay in the European Champions Cup, while Ulster are definitely through.
La Rochelle kept their hopes of progressing in the European Champions Cup alive by beating Sale Sharks, while Harlequins edged out Bath.
High-flying pair Lyon and Bordeaux Begles celebrated contrasting victories in Top 14 action on Saturday.
Bordeaux-Begles are back at the top of the Top 14 and increased their advantage over Toulon and Toulouse.
Bordeaux went above Lyon to rise to the Top 14 summit after beating La Rochelle, while All Blacks great Ben Smith saw red on his Pau debut.
Brothers Billy and Mako Vunipola played starring roles as reigning champions Saracens defeated Munster in the European Champions Cup.
There were seven tries in Leinster's 43-16 European Champions Cup win over Northampton Saints as they made it 10 victories from 10.
Lyon's lead at the Top 14 summit was reduced to just one point as they were comprehensively beaten 33-8 by Montpellier on Saturday.