Glasgow Warriors closed the gap on Munster at the top of Conference A, despite both recording wins in the latest round of Pro14 fixtures.
The Irish Rugby Football Union (IRFU) has confirmed Leinster's Robbie Henshaw has extended his contract until June 2022.
Zebre put on a spirited showing but ultimately fell short against Pro14 heavyweights Leinster.
Sean O'Brien's long stay at Leinster will come to an end following the World Cup after he agreed to join ambitious London Irish.
Devin Toner will play no further part in the Six Nations due to the damage done to his ankle in the defeat to England.
Benetton Treviso's winning run was ended at five matches as Ulster earned a dramatic draw in the Pro14.
Any hopes Toulouse had of snatching top spot in Pool 1 were extinguished as Leinster defeated Wasps to secure a home quarter-final.
Leinster have a long list of injury concerns involving Ireland internationals and Luke McGrath has now been ruled out of the Six Nations.
All four Pro14 sides in European Rugby Champions Cup action on Saturday secured victories, three coming against French opposition.
Munster moved top of Pro14's Conference A after capitalising on Glasgow Warriors' defeat to in-form Benetton Treviso.
Munster ended a four-game losing streak against Leinster with a 26-17 triumph on Saturday, while Edinburgh retained the 1872 Cup.
Connacht scored four tries but still lost out to Leinster, who rallied from 17 points down to triumph in dramatic circumstances.
Saracens battled past Cardiff Blues to stay top of Pool 3, while Toulouse came out on top in an entertaining clash with Wasps.
After helping Ireland enjoy a dominant 2018, Johnny Sexton was named the World Rugby Player of the Year.
Leinster delivered a fantastic performance against the Ospreys, racking up 52 points as seven different players crossed for tries.
Sean O’Brien had surgery on his broken arm and will be out for between eight and 12 weeks, Leinster revealed on Monday.