Scarlets claimed the scalp of Guinness PRO12 leaders Munster with a stunning 30-21 comeback win at Thomond Park.
Leinster moved to the top of the Guinness PRO12 table after hammering Newport Gwent Dragons 54-22.
Cardiff boosted their hopes of a top-six finish in the Guinness PRO12 with an 18-17 comeback win over Edinburgh.
Tommy Bowe will play his 150th game for Ulster when they take on Zebre on Sunday, live on Sky Sports 3 HD.
Bundee Aki makes his return from injury as Connacht tackle Treviso while third-placed Ospreys host Glasgow Warriors.
New Zealand-born flanker Callum Gibbins will join Glasgow on a three-year deal ahead of the 2017-18 Guinness PRO12 season.
Connacht have announced Kieran Keane has signed a three-year deal to take over as head coach next season.
Stuart Barnes on a great Sunday for the Premiership's northern clubs and concerns for Test rugby in the southern hemisphere.
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Jeremy Ward, captain of the 2016 Junior Boks, spoke to Sky Sports ahead of his debut for the Sharks on Friday.
Hat-tricks from the wings, a continental midfield pairing and try-scoring front rowers feature in our team of the week.
Will Greenwood picks his favourite moments from the week, including a referee making history in National League One.
A brilliant Stuart Hogg performance and Dylan Hartley's future feature in Stuart Barnes' Six Nations talking points.
Will Greenwood says that Owen Farrell is one of the top three players in the world and should be a contender to captain the Lions this summer.
Stuart Hogg celebrating his 50th cap with a peach of a try, CJ Stander and Lydia Thompson's hat-tricks all feature.