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.
Tommaso Boni and Jimmy Tuivaiti scored tries as Zebre got the better of Benetton Treviso as the Pro14 returned.
Benetton Treviso were prevented from playing at home last weekend because of the coronavirus, but returned to action by beating the Dragons.
More Italian sporting fixtures have been delayed by the coronavirus, with Zebre & Benetton Treviso seeing matches postponed.
Southern Kings and Benetton Treviso both fell short on Welsh soil as Scarlets and Cardiff Blues earned Pro14 wins.
The Ospreys claimed only their second Pro14 win over the season at the expense of high-flying Ulster in a stormy Swansea.
Northampton Saints and Glasgow Warriors did all they could to stay in the European Champions Cup, while Ulster are definitely through.
A thrashing of Lyon ensured Leinster made it five wins from five in the European Champions Cup, while Racing 92 reached the last eight.
Ospreys were boosted by George North's return but still could not see off Dragons in Pro14.
George Turner's late try ensured Glasgow Warriors claimed the bragging rights in their 1872 Cup clash with Edinburgh in the Pro14.
Brothers Billy and Mako Vunipola played starring roles as reigning champions Saracens defeated Munster in the European Champions Cup.
There were seven tries in Leinster's 43-16 European Champions Cup win over Northampton Saints as they made it 10 victories from 10.
Having beaten Glasgow Warriors in the Pro14 final in May, Leinster were victorious again at Scotstoun as Cian Kelleher scored a brace.
Ospreys were no match for Saracens on Saturday, while Exeter Chiefs were among the other European Champions Cup winners.
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.
Munster were delighted to have Andrew Conway back in Pro14 action as he settled an all-Irish affair with Ulster.