Alesana Tuilagi's try double helped Leicester to a bonus-point victory at Welford Road.

Tuilagi's last-gasp effort in the defeat at London Irish on Boxing Day secured a couple of bonus points and the burly winger grabbed one in each half against Saracens in a top four clash.

He was denied a hat-trick in the third quarter when the referee ruled there had been a knock-on.

Ben Kay claimed a crucial try in first-half injury-time for Leicester and they also forced a penalty try as they hit back from going behind to a Kevin Yates try after 13 minutes.

Leicester made 12 changes to the side beaten at London Irish, with Ben Kay, Geordan Murphy and Alesana Tuilagi the only players to keep their places as Leo Cullen captained the side.

Saracens went into the game having won four of their previous five games in the Premiership to climb to fourth, and director of rugby Alan Gaffney had skipper Yates, Richard Hill, Andy Farrell, Iain Fullarton and Thomas Castaignede back in the starting line-up.

Gaffney also handed a first start to former Leicester academy player Tim Taylor.

Saracens had never won in 30 previous visits to Welford Road, and were soon pinned back in their own half.

Leicester missed a chance to go ahead in the seventh minute when fly-half Ian Humphreys was off target with a penalty attempt, and Tigers were stunned when the visitors went in front after 13 minutes.

Taylor's grubber kick set up a line-out 10 metres from the Leicester line, and a series of drives ended with Yates squeezing over in the left-hand corner. Castaignede's conversion attempt was wide.

Tuilagi failed to gather Humphreys' pass when he had the line at his mercy after 21 minutes, and had more success three minutes later.

Tuilagi gathered scrum-half Scott Bemand's inside pass and galloped in unchallenged from 20 metres for a try that Humphreys converted to make the score 7-5.

Farrell's penalty in the 32nd minute put Saracens back in front, before Tigers grabbed a second try in the dying seconds of the half. Kay ploughed over following a driving maul, and Humphreys converted to put Leicester 14-8 ahead at the break.

Tigers went further clear seven minutes after the restart when Tuilagi picked up a loose ball to cross after Saracens had fumbled and Humphreys hacked on.

Humphreys added the conversion to open up a 21-8 lead before Census Johnson crossed after 53 minutes for a try that Farrell converted to close the gap to six and hand Saracens a lifeline.

But their chances were dented after 61 minutes when Yates was yellow carded following a string of infringements and Leicester cashed in to force a penalty try moments later after a succession of collapsed scrums.

That secured a bonus point and Humphreys added the conversion to complete the scoring.