Northampton Saints were brought back down to earth after they suffered a 50-28 loss away to Champions Cup holders Bordeaux in a repeat of last season's final.
Adam Radwan scored two tries as Leicester kept in contention for a play-off spot with an impressive 36-28 win over Saracens.
Northampton stunned the Prem Rugby champions Bath with a devastating display of running rugby featuring a hat-trick of tries by freewheeling England back Tommy Freeman.
Munster bounced back from a disappointing defeat to Bath last week to comprehensively beat Gloucester 31-3 in the Champions Cup at Páirc Uí Chaoimh in Cork.
An astonishing start which saw Bath 28-0 ahead inside 19 minutes proved crucial as the Prem side saw off Munster 40-14 in their Champions Cup opener.
Bath snatched a 36-29 victory over Saracens that propelled them two points clear at top of the Gallagher Prem.
Tommy Freeman ran in four tries as Northampton Saints fought back to defeat Saracens 43-31 in Gallagher Prem clash.
On Saturday, a 19-year-old by the name of Noah Caluori stunned the rugby world by remarkably scoring five tries for Saracens vs Sale Sharks on his first Prem start.