Saracens survived a late fightback from Northampton to stretch their lead at the top of Premiership to 10 points.
The London team, who seem almost certain now to end top of the log, were cruising at 28-10 in the 72nd minute, when England centre Luther Burrell and Wales wing George North touched down within three minutes of each other, setting up a tense finale.
David Strettle, Kelly Brown and Marcelo Bosch crossed for tries to celebrate Saracens captain Steve Borthwick's record-breaking 263rd Premiership appearance.
Saints stayed in second place, but edged three points ahead of chasing Leicester by virtue of their losing bonus point.
The Leicester Tigers turned up the heat on Saturday with a four-try win over Wasps at Welford Road. England centre Manu Tuilagi scored two to take his total to three in five games since his return from injury.
Meanwhile, the Rugby Football Union is to investigate Saturday's ill-tempered match between Gloucester and Bath, which ended with a mass punch-up, a fan reportedly throwing a bottle at referee Tim Wigglesworth and only 11 Gloucester players on the field. Gloucester scrumhalf Tavis Knoyle was sent off for throwing punches and sparking the brawl, joining prop Sila Puafisi, who was red-carded for a dangerous tackle. Centre Mike Tindall and hooker Huia Edmonds were sitting in the sin-bin. Bath were not entirely innocent, having seen three yellow cards during the match.
Bath won 18-17 with a last-minute penalty try, converted by George Ford.
In a basement battle on Sunday, London Irish put some distance between themselves and Newcastle with a 40-12 win; with all points being scored in the first half.
Saracens 28 Northampton 24
London Irish 40 Newcastle 12
Sale 12 Harlequins 27
Leicester 27 London Wasps 15
Worcester 33 Exeter 38
Gloucester Rugby 17 Bath 18
Photo: David Rogers/Getty Images