Holders Saracens are a win away from the Champions Cup final after beating Leinster, while Racing 92 powered past Clermont Auvergne.
Shining Arcs will have Greig Laidlaw, Liam Gill and Anaru Rangi in their squad when the Top League season gets under way in 2021.
A five-week break has been implemented in the Premiership, with the Champions Cup and Challenge Cup quarter-finals pushed back.
Bordeaux Begles gave another demonstration of their Top 14 title credentials with a bonus-point win over Clermont Auvergne.
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.
Rhys Carre's early red card made life difficult for Saracens, but they still defeated Ospreys in the European Champions Cup.
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.
Fly-half Greig Laidlaw said it was an "incredibly hard" decision to retire from international rugby.
Brothers Joe and Sam Simmonds were influential as Exeter Chiefs moved to the brink of a quarter-final spot in Europe.
Bath were no match for a classy Clermonth Auvergne in Friday's European Rugby Champions Cup clash.
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.
Ulster made it two wins from two in this season's European Champions Cup by overcoming Pool 3 rivals Clermont Auvergne.
Ireland centre Garry Ringrose was the star of the show as Leinster started their bid to regain the Champions Cup with a bonus-point win.
Toulouse's contrasting home and away form continued as they defeated visitors and 2018-19 Top 14 final opponents Clermont Auvergne.