Cheslin Kolbe starred for Toulouse against Ulster, while Exeter Chiefs got the better of Northampton Saints in the European Champions Cup.
Leinster cruised to a record seventh Pro14 title as they defeated fellow Irish side Ulster 27-5 in Dublin in Saturday's final.
There will be an all-Irish final in Pro14 after Ulster came from behind to defeat Edinburgh and book a date with Leinster.
The Scarlets can still quality for the Pro14 play-offs next week after beating the Dragons, but they need Connacht to do them a favour.
The Ospreys were on the verge of victory despite George North's early red card, but Ashton Hewitt's try salvaged a draw for the Dragons.
Jordi Murphy and Will Addison have signed contract extensions with Pro14 side Ulster.
More Italian sporting fixtures have been delayed by the coronavirus, with Zebre & Benetton Treviso seeing matches postponed.
After losing to Ospreys, Ulster bounced back by defeating Cheetahs, while Glasgow Warriors beat Dragons to move into third in Conference A.
Ulster maintained their unbeaten home record in the Pro14 with an emphatic win over Munster, who slipped off the top of Conference B.
Pro14's Conference A leaders Leinster dismantled second-placed Ulster on Friday, scoring eight times before the beaten visitors rallied.
Juan Imhoff scored two of Racing 92's six tries as they beat Ospreys 40-27 to increase their lead at the top of Pool 4.
Eroni Sau's try proved decisive as Edinburgh saw off Pro14 Group B leaders Munster, while Ulster thrashed Scarlets on Friday.
Ulster made it two wins from two in this season's European Champions Cup by overcoming Pool 3 rivals Clermont Auvergne.
Undefeated Leinster made light work of the Dragons as Glasgow Warriors thrashed Southern Kings 50-0 on Friday.
Munster top Pro14 Conference B after their 28-12 victory over Ospreys, while Cardiff Blues were defeated 23-14 by Ulster.
Scarlets made it three from three in Pro14 on Sunday as Glasgow Warriors earned a first win of the season.