Premiership: Harlequins 12-22 Saracens
Saracens maintained the only 100% record in the Premiership this season by winning at the home of fellow title contenders Harlequins.
Chris Ashton crossed for the only try to keep Sarries top of the table.
Earlier, Nick Evans had kicked four first-half penalties to put the hosts 12-6 ahead at the interval.
But Owen Farrell produced a near-faultless display from the tee, contributing 17 points to earn a fourth victory in four games for the visitors.
In a meeting between two of the sides expected to be challenging for the Premiership crown in May, Saracens were rewarded for their second-half dominance. Their failure to collect a bonus point, having done so in their previous three matches this season, was only a minor disappointment.
As for Conor O'Shea's men, who lie fifth in the standings, they have now lost both of their home fixtures at the Stoop so far this term.