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.
The Crusaders drew for the second time in three weeks in their match against the Stormers, while the Lions edged a 10-try battle.
Northampton Saints took the final Premiership play-off spot despite losing to Exeter, while Bath secured Champions Cup rugby next term.
Munster gave it a great go, but Leinster have the chance to be crowned Pro14 champions once again.
The Blues kept their Super Rugby play-off hopes alive, while the Reds were beaten in a tense encounter with the Waratahs.