Defiant Saracens ruined Harlequins’ record-breaking Christmas party and ended their unbeaten start to the Aviva Premiership season with a ferocious defensive performance at sold-out Twickenham.
Owen Farrell kicked 14 points and David Strettle scored against his former club as Saracens raced into a match-winning 19-3 lead after just 24 minutes.
Harlequins attempted a comeback and prop Joe Marler, whose pass had been intercepted by Strettle, scored in a dominant second-half performance from the hosts.
Saracens did not score another point but they defended resolutely to seal the 19-11 victory in front of 82,000 supporters and close the gap on league leaders Harlequins to five points.
The extraordinary crowd was a world record for a regular-season club fixture, beating the 79,842 that watched Stade Francais v Clermont Auvergne in the French Top 14.
London Irish moved third after a tough 29-22 win over Exeter at the Madejski Stadium.
Toby Flood scored a try and kicked 12 points, as Leicester extended their unbeaten run to five games after brushing Worcester aside 32-13 at a sold-out Sixways.