Webb had an eventful game, with two tries and a yellow card

Harlequins: (16) 20
Tries: Sykes, Hill, McLinden, Orr
Goals: Sykes 2

Leeds: (6) 54
Tries: Thackray, Webb 2, Tansey, Ellis, Sinfield, Donald, Peacock, McGuire
Goals: Sinfield 7, Tansey 2

Leeds kept the pressure on St Helens at the top of Super League as they mounted a ferocious fightback to condemn Harlequins to a humiliating defeat.

Quins totally dominated the first 40 minutes, stretching to a 16-6 half-time lead courtesy of tries from Paul Sykes, Scott Hill and Mark McLinden.

Brent Webb crossed on 48 minutes for Leeds, and Harlequins wilted in the summer heat at the Twickenham Stoop.

Webb rounded off the demolition in the final minute with Leeds' ninth try.

In scorching hot conditions, it did not take long for tempers to boil over with two high tackles in quick succession from Webb providing the catalyst.

Both incidents were placed on report, and Quins quickly punished Leeds' indiscipline with a lovely cut-out pass from McLinden finding Sykes in space out wide.

Leeds briefly went ahead when Kevin Sinfield converted Jamie Thackray's score after the replacement had sidestepped his way past Lee Hopkins.

Webb found himself back in the stands for 10 minutes after referee Phil Bentham finally lost patience, and handed him a yellow card for a third high shot.

Again, Quins made Leeds pay and Hill went through some half-hearted Leeds tackling to put his side back ahead.

A glorious try from McLinden, after great work from Jon Wells and Danny Orr, followed and the home side went into a welcome half-time break with a 10-point lead.

But the second half was a disaster for Harlequins, with Webb's try - after Scott Donald had already gone close - opening the floodgates.

An outstanding 40/20 kick from Danny McGuire proved a significant turning point, with Jordan Tansey soon collecting his own grubber kick to score and bring Leeds level.

Any doubts about the match's outcome were effectively sealed when Sinfield, playing as a stand-in hooker, powered through three tackles to score.

Quins were visibly tiring, with coach Brian McDermott quickly running out of interchange options after making seven in the first half.

After forcing a repeat set, Gareth Ellis received an inside ball from McGuire to stroll over for a simple score, quickly followed up by Donald's long-range try and another easy score for Jamie Peacock.

Orr scored a consolation try for Quins but the match was over as a contest, a fact confirmed by late scores for McGuire and Webb.

"We were very good defensively in the first half.

"If rugby league was a 40-minute game we would have won that, but Leeds came out of the dressing-room white hot.

"We certainly showed areas of the game that can get us into the play-offs. We just need to do more of the things in the good areas and less of the bad.

" "Leeds got on a roll in those conditions and a couple of silly errors from us let them back in it."

"At half-time I had a lot of faith in my own players but I still had a lot of respect for Harlequins.

"We have answered some questions of ourselves and came up with a pretty good performance.

"Brent Webb put us under pressure in the first half, and I think he felt that as well, but he did something about it and paid us back - he was a big contributor in the second half.

"His form is very good and that is a confidence boost to him."

Harlequins: McLinden, Wells, Sykes, T. Smith, R. Sheriffe, Hill, Orr, Temata, Randall, McCarthy-Scarsbrook, Gafa, Hopkins, Paul.
Replacements: Rinaldi, Purdham, Grayshon, Mbu.

Leeds: Webb, Donald, Toopi, Senior, Hall, McGuire, Burrow, Bailey, Sinfield, Leuluai, Jones-Buchanan, Peacock, Ellis.
Replacements: Thackray, Tansey, Lauitiiti, Kirke.

Referee: P Bentham (Warrington)