Wasps, without Christian Wade, battled back to draw with Bath, and Edinburgh battered Toulon in Saturday's European Champions Cup action.
England will be without Nathan Hughes for three of their November internationals after he was banned for six weeks.
Leinster accelerated out of sight in the second half of their European Champions Cup opener as Wasps were completely outclassed.
Wasps forward Joe Launchbury will be out for up to three months after the club confirmed he had surgery on his injured knee.
Wasps fought back from a 22-13 deficit in the second half at Kingston Park to secure a third successive win in the Premiership.
Northampton Saints slumped to a third defeat in four as Bath won at The Rec, while Wasps and Bristol also secured victories.
The Ricoh Arena played host to a Premiership classic on Sunday as Wasps overcame 14-man Leicester Tigers 41-35 in an eight-try thriller.
Flanker Brad Shields will start his first Premiership game on Saturday when Wasps host last season's beaten finalists Exeter Chiefs.
Danny Cipriani produced a sensational pass for Charlie Sharples' try while Billy Twelvetrees kicked 17 points in Gloucester's victory.
Jimmy Gopperth will miss much of the new season as a result of cruciate ligament damage sustained against Connacht.
Ashley Johnson can return to action for Wasps next month after being handed a backdated six-month ban for a positive anti-doping test.
Leinster will have to see off three former champions if they are to retain their European Champions Cup title in 2018-19.
Danny Wilson's move to Wasps is no longer happening as the club reached an agreement with Scotland for him to be Greg Townsend's assistant.
Jack Willis sustained significant multi-ligament knee damage against Saracens and faces a long road to recovery.
Brad Shields will leave New Zealand to play international rugby for England but Steve Hansen said he was thinking of calling him up.
Joe Simmonds kicked 19 points as defending Premiership champions Exeter Chiefs set up a Twickenham showdown with Saracens for the title.