Racing 92 boosted their hopes of qualifying for the European Champions Cup by thrashing bottom side Perpignan 52-14, while Lyon's win over La Rochelle confirmed they will have a home quarter-final in the Top 14 play-offs.
Perpignan were already relegated and they were heavily beaten in their final home fixture as Racing ran in eight tries to move up to fourth in the table on Saturday.
Six of those scores were shared equally between two men – Louis Dupichot and Simon Zebo each grabbing hat-tricks – while Dominic Bird and Finn Russell also touched down.
Jonathan Wisniewski's 19 points with the boot helped Lyon to a 29-19 victory that saw La Rochelle slip out of the top four.
Charlie Ngatai's try saw Lyon move ahead in the 51st minute, with Wisniewski slotting over two conversions, four penalties and a drop goal in a fine individual performance.
Castres also moved above La Rochelle into fifth as Wilfrid Hounkpatin and Loic Jacquet crossed either side of half-time in a 17-10 success over Agen.
Pau ensured their safety with a 22-0 triumph over Grenoble, who will contest a relegation play-off.