Harlequins won an entertaining encounter with Exeter Chiefs to hand them their first defeat of the Premiership season.
There were Premiership wins for Newcastle Falcons and Worcester Warriors on Friday, with the former moving off the foot of the table.
Gloucester had Danny Cipriani back from a ban and the fly-half was instrumental in their bonus-point 36-13 win over Leicester Tigers.
Connacht had no answer to Chris Ashton, who enjoyed a hat-trick on his competitive debut for Sale Sharks.
Eddie Jones has lost another influential figure in the back-row, with former captain Chris Robshaw out for up to eight weeks.
Worcester Warriors had lost 11 away games in a row in the Challenge Cup, but ended that sequence with a brilliant showing in Paris.
Saracens are level with Exeter at the top of the Premiership after fighting back to beat Harlequins.
Prop Joe Marler said comments he made on a podcast about looking for an "easy way out" of England duty were taken out of...
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Saracens and Exeter Chiefs met in last term's Premiership final and they are making the early running once more this season.
Harlequins forward Joe Marler said it was "a very difficult decision" to end his England career at the age of 28.
Northampton Saints slumped to a third defeat in four as Bath won at The Rec, while Wasps and Bristol also secured victories.
Saracens needed two late tries from David Strettle to secure a come-from-behind victory over Northampton Saints.
Dan Biggar kicked 17 points and Dylan Hartley came off the bench to score a try as Northampton Saints edged out Harlequins.
Danny Cipriani produced a sensational pass for Charlie Sharples' try while Billy Twelvetrees kicked 17 points in Gloucester's victory.
Paul Lasike returned to rugby after a stint in NFL and has now earned a contract with Premiership side Harlequins.
Eddie Jones will lose a prominent member of his England backroom team, with Harlequins appointing Paul Gustard as head of rugby.