Francisco Leonelli scored a 15 minute hat-trick as Saracens cruised to a landslide 66-7 victory over Leeds Carnegie, their biggest ever Premiership league win at Vicarage Road this afternoon.

The Argentina international, a summer signing from Glasgow Warriors, had not scored in 11 previous outings this season, yet the blue-booted speedster did not have to do a great deal for his first points in black and red colours.

Saracens had the game - and only their second try scoring bonus point of the season - won by half time.

Tries for Nick Lloyd and Adam Powell punctuated Leonelli's superb treble while fly-half Glen Jackson succeeded with all but one conversion to give Sarries a deserved 33-0 half time lead.

Hugh Vyvyan and replacement Tom Ryder added early second half scores before Kameli Ratuvou added an eighth with 16 minutes left.

Glen Jackson then reclaimed his place at the summit of the Premiership's top points scorers by converting his own 71st minute try.

Doomed Leeds avoided a whitewash when former Sarrie Stuart Hooper crossed with five minutes remaining.

However, Sarries had the last word when Brent Russell hared over for their tenth try.

Saracens started brightly with the backs moving the ball about with confidence and verve before Brent Russell's pass to Kevin Sorrell strayed forward.

Wing Kameli Ratuvou then left several Leeds players trailing in his wake down the left before Hendrie Fourie and Joe Bedford teamed up to hold up the Fijian on the line.

It was only delaying the inevitable, however, as prop Lloyd crashed over from a destructive rolling maul with six minutes on the clock. Jackson added the extras.

Full-back Leigh Hinton's first penalty of the game struck the posts as Leeds struggled to gain a foot-hold.

Sarries extended their lead in the 18th minute after taking advantage of some dire Leeds defending.

After taking Neil de Kock's pass at the Leeds 22, Jackson was allowed to ghost past rooted Carnegie centre Rob Vickerman where he drew the cover and put in Leonelli for his first try of a stop-start season for the injury-prone Argentina international.

Three minutes later Sarries crossed the line for the third time when Adam Powell's show and go left Leeds all at sea as the young centre breezed across the whitewash. Jackson converted for 21-0.

Attack appeared to be the best form of defence for the struggling visitors but a knock-on by Hinton after they had created a sizeable overlap on the left summed up their dismal season.

Leonelli then secured the try bonus point with his second of the afternoon after 28 minutes. After recalled hooker Matt Cairns had burst through a gap in midfield, good hands by Jackson put Kris Chesney on the charge. The flanker threw a miss-pass out to Russell who quickly off-loaded to the supporting Leonelli.

The blue-booted wing then completed his treble after squriming over in the right corner following some more delightful back play across the park. Jackson made no mistake with the conversion to give his side a commanding 33-0 half time lead.

Sarries maintained the intensity they showed in the first half and Hugh Vyvyan scored their sixth try of the afternoon just six minutes into the restart after a lung-busting run from Ratuvou saw the lock ground his team-mates' grubber kick.

Russell was then held up in the corner as Leeds struggled to contain wave after wave of Sarries attacks.

Replacement second row Tom Ryder then barged over as the blood-letting continued.

Ratuvou's try got Sarries to the half century mark before a fantastic wrap-around between replacement Andy Farrell and Jackson put the Kiwi in for a 71st minute try, which he converted.

Leeds, now staring down the barrel of relegation, ensured they did not leave Watford scoreless as American prop Mike Macdonald seized upon a sloppy Jackson pass to put in skipper Stuart Hooper under the posts. James Brooks added the extras.

Russell then put the gloss on a superb Men in Black display with the tenth try following fine kicks from Kevin Sorrell and Ratuvou.

The result is a timely confidence booster ahead of next weekend's historic Heineken Cup quarter final with the Ospreys.

Saracens: Russell, Leonelli, Sorrell, Powell, Ratuvou, Jackson, de Kock (cpt); Lloyd, Cairns, Johnston, Vyvyan, Chesney, Gustard, Barrell, Skirving.

Referee: Rob Debney. Attendance: 5,896.

Scoring sequence: 5-0/7-0/12-0/14-0/19-0/21-0/26-0//31-0/33-0 HT/38-0/43-0/45-0/50-0/52-0/57-0/59-0/59-7/64-7/66-7.