Chris Ashton's fourth try of the season edged Saracens one step closer to a home Aviva Premiership semi-final as they beat London Wasps at Adams Park to cement their place at the top of the table.
Sarries were forced to come from behind after Christian Wade's interception try had given Wasps a first-half lead but Ashton and Chris Wyles crossed the whitewash to turn the game around.
Mark McCall's side can now secure a home tie in the Premiership semi-finals with a bonus-point victory in the next round after Harlequins and Northampton lost their respective matches, though Leicester Tiger's victory over the latter saw the gap at the top closed to four points.
Sarries started with pace, attacking the Wasps line well but their early efforts ended with a dropped ball just outside the hosts 22.
Wasps' first points came after the pack gave the Saracens scrum real problems on half-way, winning a penalty which Elliot Daly slotted to make it 3-0 after eight minutes.
Sarries came back looking to move the ball, but Wasps flyer Wade read Charlie Hodgson's pass to intercept and sprint in from 50 metres. His tenth try of the season was converted by Stephen Jones to make it 10-0.
A late tackle on Jones enabled Daly to extend the home side's lead to 13-0 before Saracens struck back with an opportunistic score.
Alex Goode caught the Wasps defence napping with a tap penalty and attacked the left wing, creating a two on one which Wyles finished to bring the score to 13-5.
Sarries had their tails up and a series of messy scrums earned Owen Farrell a shot at goal, but the England fly-half - playing at centre - was unsuccessful.
Farrell found his kicking boots with 13 minutes of the half left, knocking over a 38m penalty to cut the gap to 13-8.
Sarries prop Mako Vunipola nearly scored five minutes before half-time, but after crashing through from a few metres out he was thwarted by a tackle from brother Billy and Joe Launchbury.
Mouritz Botha saw yellow right before the break for deliberately knocking the ball to the ground and Wasps took control in the early stages of the second-half with him off the field, spraying the ball across the field, but they failed to find a gap in the Sarries defence.
Momentum began to swing Saracens way and Farrell cut the gap to 13-11 with a penalty before Ashton bagged his try.
Goode nudged a grubber kick down the right wing and Ashton gathered to score before Farrell failed to convert but he slotted another penalty to extend the lead to 13-19.
Rhys Gill nearly scored for Saracens four minutes from time but knocked the ball on five metres from Wasps try line before one final penalty from Farrell made the points safe and condemned Wasps to a fourth consecutive Aviva Premiership defeat.