Abraham Papali'i and Shane Delahunt were sent off in the second half and Munster capitalised to move into the last four of the Pro14.
Ollie Thorley scored four first-half tries in Gloucester's win against Leicester, while two Exeter hat-tricks helped to crush Worcester.
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.
Sale Sharks played with swagger as they crushed Bristol on Saturday in the Premiership, climbing to second place in the process.
The Rebels are on the verge of securing a place in the Super Rugby AU finals despite a 38-32 defeat to the Waratahs on... Read more
Danny Wilson got his maiden Pro14 win as Glasgow Warriors' new coach on Friday, though the 15-3 victory over Edinburgh was unspectacular.
The ruthless Brumbies scored five tries to see off Western Force and ensure they will be at home in the final on September 19.
Worcester Warriors won their first game of 2020 on Wednesday, while Bath's strong second-half display led them to a third win a row.
A last-gasp try from Billy Keast gave Exeter Chiefs a dramatic late win over Bristol Bears.
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.
Leinster picked up where they left off in the Pro14 as they held off Munster in a thrilling contest in Dublin on Saturday.
Harlequins were unable to recover from a dominant first-half display by rivals Saracens at Allianz Park.
There were comebacks for leaders Exeter Chiefs and Wasps in Friday's Premiership action.
Tommaso Boni and Jimmy Tuivaiti scored tries as Zebre got the better of Benetton Treviso as the Pro14 returned.
James O'Connor scored a try and kicked 17 points as the Reds achieved a record win over Western Force on Friday.
An impressive showing from Wasps saw them claim a bonus-point win over Northampton Saints at Franklin's Gardens on Sunday.