Vicky Fleetwood scored for Saracens on her 50th appearance for the club
A comeback from Bristol Bears earned them a 24-17 victory at West Country rivals Gloucester-Hartpury.
The visitors were 10-0 down at half-time, but made it two wins from two at the start of their Premier 15s campaign.
"It was such a tight game. I'm under no illusions it could have gone either way," said Bears coach Dave Ward.
"I'm just so happy and proud for the girls that we came out on the right side of it."
The game was tied 17-17 when Rownita Marston scored a late try to seal Bristol's success, adding to two earlier from Phoebe Murray and one from Hannah West.
Elsewhere, Saracens ran in 13 tries - including one for Vicky Fleetwood on her 50th appearance for the club - as they thrashed Durham Sharks 77-5, while Harlequins won 66-31 at Worcester Warriors.
There were also comfortable wins for Exeter Chiefs and Wasps on Sunday.
Exeter were dominant 54-0 victors against Sale Sharks, while Wasps, with the help of Abby Dow's 50th try for them, beat Loughborough Lightning 29-0.
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