Lee Smith signed off his Leeds career with a match-winning double as the Rhinos secured an unprecedented hat-trick of engage Super League titles in a defence-dominated Grand Final.

Smith, man of the match in the 24-16 win over St Helens a year ago, scored a try in each half to deliver a memorable leaving gift to his team-mates as he prepares to switch codes with Wasps.

The England centre's second try came eight minutes from the end of a pulsating match which hung in the balance until the champions finished with something of a flourish in front of a crowd of 63,259 at Old Trafford.

The outcome was tough on Saints' 20-year-old centre Kyle Eastmond, who scored all his side's points in another demonstration of his exciting potential.

It was also a sad way for Sean Long to end his 12-year stay with the club as St Helens became runners-up for the third year in a row and finished the season empty-handed for the first time since 2003.

Mick Potter's men produced the defence that served them so well in their earlier play-off wins over Huddersfield and Wigan but once more failed to spark in attack.

Stand-off Leon Pryce was unable to impose himself on the game as Saints failed to score more than 15 points for the ninth successive match.

Leeds were also not at their fluent best but overcame the loss of replacement second rower Ali Lauitiiti, who hobbled off five minutes before half-time, and defended superbly to concede just one try.

That came 13 minutes into the game when Jon Wilkin's kick came off the side of Leeds captain Kevin Sinfield's boot and bounced kindly for Eastmond to touch down.

The youngster converted his try and made it 8-0 on 26 minutes with a penalty after

Keith Senior was punished for obstruction.

Leeds spent most of the first half inside their own half and were indebted to the superior kicking of man of the match Sinfield and half-backs Danny McGuire and Rob Burrow to get them out of trouble.

And the champions showed their mettle with two tries in the last 11 minutes of the half to deservedly draw level.

Hooker Matt Diskin used brute force to reach the line on the last tackle and Smith demonstrated opportunism to score after Saints winger Francis Meli failed to palm the ball dead from McGuire's kick.

Sinfield hit an upright with his first conversion attempt and was wide with his second but was on target with a drop goal 80 seconds into the second half to give his side the lead for the first time.

It seemed a strange tactic with so much time left but Sinfield clearly expected a close battle to the end and he was right.

The Rhinos had a let-off when Matt Gidley freed Ade Gardner down the right flank only for the winger to lose control of the ball over the line, but Saints regained the lead with Eastmond's second penalty.

That was the result of a high tackle from, of all people, the 5ft 5in Burrow on his opposite number Long, but Sinfield responded with his first successful goal after Saints skipper Keiron Cunningham was pulled up for interference at the play-the-ball.

Leeds survived another scare when the strong-running, if error-prone, Meli got Eastmond haring for the corner and slow-motion replays showed he brushed the corner flag before touching down.

The drama heightened when Diskin got over the line only to be held up but the pressure paid off when Smith successfully chased McGuire's kick to pounce for his second try.

There was a suspicion of offside but the try merely confirmed the inevitable and Sinfield's goal, along with Burrow's last-minute drop goal, wrapped up a deserved victory.