Glen Jackson bagged an 18-point haul to keep alive Saracens' dreams of Guinness Premiership glory.

The New Zealander, top scorer in the Premiership this season, kicked 13 points and also crossed for a try to move Sarries up to third in the table and push them to the brink of play-off qualification.

With Wasps' win over Northampton earlier in the day the pressure was on the home side to deliver and they responded with a four-try bonus point performance.

It was Saracens' 10th successive home win in all competitions and ensures their play-off fate remains in their own hands.

Despite the high stakes the home side showed no signs of nerves and dominated the opening quarter.

After Jackson struck an early penalty Saracens twice came close to scoring the opening try when both Neil de Kock and Richard Hill spilled the ball with the line at their mercy.

It was England stalwart Hill who was to create the first five-pointer though, bursting through a couple of tackles and allowing Kris Chesney to cross in the corner.

Jackson soon kicked another penalty to extend their lead as a shell-shocked Quins struggled to get out of their own half.

However, as the half wore on All Black outside half Andrew Mehrtens began to find his range with touch finders and pinned the home side back in their 22.

Quins were rewarded for their efforts when Mehrtens and Simon Keogh combined to allow Mel Deane to crash over.

More worrying for the visitors though was the sight of England flyer David Strettle limping off with an ankle injury sustained in the build-up to the try.

Although Jackson struck another penalty Harlequins stunned the large home crowd with a score right on half-time.

Stealing possession right on halfway, Mehrtens kicked ahead and replacement Tom Williams won the chase to score.

Saracens quickly reasserted their dominance at the start of the second half and produced another period of adventurous play that had Quins gasping. It was no surprise that another try was quickly forthcoming.

Sarries' forwards barged up field and de Kock delivered a defence-splitting pass for French full-back Thomas Castaignede to race over under the posts.

With Jackson converting the home side had breathing space and they maintained a stranglehold on proceedings despite a determined showing from the visitors.

Saracens produced two late tries to secure both the victory and a precious bonus point.

Firstly Jackson and Andy Farrell exchanged passes to free Dan Scarborough to touch down in the corner.

And with time running out Jackson was on hand to finish off a flowing move and cross the line.

Quins still had time to score a consolation try with Mike Brown crashing over.

Saracens (14) 33
Tries: Chesney, Castaignede, Scarbrough, Jackson
Con: Jackson (2)
Pen: Jackson (3)

Harlequins (12) 19
Tries: Deane, Brown (2)
Con: Mehrtens (2)

Saracens: 15. Thomas Castaignede, 14. Dan Scarbrough, 13. Kevin Sorrell, 12. Andy Farrell, 11. Rodd Penney, 10. Glen Jackson, 9. Neil De Kock, 1. Kevin Yates, 2. Matt Cairns, 3. Census Johnson, 4. Hugh Vyvyan, 5. Simon Raiwalui, 6. Kris Chesney, 7. Richard Hill, 8. Ben Skirving

Replacements: 16. Fabio Ongaro, 17. Tom Mercey, 18. Paul Gustard, 19. David Seymour, 20. Moses Rauluni, 21. Adam Powell, 22. Tomas De Vedia

Harlequins: 15. Mike Brown, 14. David Strettle, 13. Mel Deane, 12. Tosh Masson, 11. Simon Keogh, 10. Andrew Mehrtens, 9. Andy Gomarsall, 1. Ceri Jones, 2. Tani Fuga, 3. Mike Ross, 4. Ollie Kohn, 5. Jim Evans, 6. Andre Vos, 7. Paul Volley, 8. Chris Hala'ufia

Replacements: 16. James Hayter, 17. Ricky Nebbett, 18. Simon Miall, 19. Tom Guest, 20. Will Skinner, 21. Steve So'oialo, 22. Tom Williams