Racing 92 ran out of time in their defeat to Toulouse, while La Rochelle survived a Top14 scare against lowly Grenoble.
Racing 92 have some pretty formidable back-up for Finn Russell with Dan Carter returning to the Top14 club.
Clermont had not been beaten since October, but they were brought back down to earth by Top 14 champions Castres.
A spectator who abused Simon Zebo during Ulster's Champions Cup meeting with Racing 92 has been given a lifetime ban by the Pro14 club.
Saracens and Racing 92 secured home quarter-finals in the Champions Cup but the hopes of Exeter Chiefs are over after defeat at Munster.
At the age of just 28, former Springbok Patrick Lambie has retired from professional rugby, his club Racing 92 have announced.
All four Pro14 sides in European Rugby Champions Cup action on Saturday secured victories, three coming against French opposition.
Racing 92's win over Toulon will not have made pleasant viewing for France coach Jacques Brunel as Teddy Thomas was injured.
Toulouse ended 2018 on a high note, dishing out a crushing defeat to Toulon in one of three Top 14 games on Sunday.
Stade Francais moved up to fifth in the table as Toulon and Racing 92 ran out convincing winners in Saturday's Top 14 action.