Saracens prevented Harlequins from scoring in the second half at the Stoop to seal a 22-12 win in the Aviva Premiership.
Nick Evans kicked four penalties in the first half as Quins claimed a slender 12-6 lead at the break, with try-scoring opportunities few and far between for both sides.
Chris Ashton allowed Saracens to take the lead for the first time in the 50th minute with the only try of the contest.
Fly-half Owen Farrell kicked the remainder of the points for the visitors, missing just one of his seven attempts at the posts this afternoon.
The result moves Saracens to the top of the table, while Quins drop to fifth.
