The Dragons have parted ways with head coach Bernard Jackman, who was appointed to the role at the Pro14 club in June 2017.
The Crusaders' assistant coach Brad Mooar will take over from Wayne Pivac in the top job at the Scarlets from 2019-20.
Alex Allan's dismissal did not prove costly as Glasgow Warriors beat the Scarlets, while Leinster scored 59 in a victory over the Dragons.
Three tries in eight minutes from Keith Earls helped Munster to an easy win over Edinburgh, while Ospreys nilled Zebre.
After helping Ireland enjoy a dominant 2018, Johnny Sexton was named the World Rugby Player of the Year.
Jared Rosser scored two tries as the Dragons claimed a much-needed victory in Sunday's Pro14 action.
The Cheetahs claimed their second Pro14 win of the season as Daniel Maartens crossed twice in the final 21 minutes against Benetton Treviso.
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.
Stuart Hogg said the time has come to challenge himself in a different environment after nine seasons with Glasgow Warriors.
Gethin Jenkins dragged a shot at goal wide after requiring assistance to keep the ball on the tee in a victorious final match.
Glasgow Warriors stretched their lead at the top of Conference A to nine points thanks to Nikola Matawalu's hat-trick against Ospreys.
Gethin Jenkins, Wales' most capped player, will retire from rugby this weekend.
Munster overturned a 14-point deficit to beat Glasgow Warriors thanks to Rory Scannell's monster penalty with the final play.
Zebre stunned Edinburgh, Scarlets denied Southern Kings and there was landmark win for Ulster in Pro14 on Friday.
Ireland winger Keith Earls has admitted it is hard to imagine him playing anywhere else after extending his stay with Munster.