Bluey's Babes saw a 20-point lead turned into a four-point deficit as Harlequins half-backs Danny Orr and Henry Paul took the game by the throat, sharing four tries in 12 second-half minutes.

The Londoners would almost certainly have taken a place in the quarter-finals had Will Sharp's 73rd minute touchdown not been disallowed.

The winger got over by the flag, only for referee Ian Smith to rule that David Howell's pass had been forward.

The ball looked good from the press box, but Rhinos took advantage of their lucky break.

Chasing the game, Rhinos had failed to make headway against an excellent home defence, but – after that let-off – three of their senior men came up with big plays to save the day right at the death.

Firstly, skipper Kevin Sinfield made use of an off-season rule change, kicking into touch from a 20-metre re-start to earn Leeds an attacking scrum.

In the subsequent set, Danny McGuire and Jordan Tansey – who started at hooker and made an important contribution late on at full-back – went close before Jamie Peacock collected the ball from acting-half to power jubilantly over.

Sinfield's conversion gave Leeds a four point lead and once Ryan Hall had dealt with the short re-start, Quins' chance had gone.

Forced to push things in the final moments, Jon Grayshon's offload was snapped up by McGuire and a couple of tackles later he completed a fine hat-trick, crossing from Matt Diskin's pass with Sinfield's sixth conversion from as many attempts completing the scoring after the hooter.

Quins scrum-half Orr was the game's outstanding player, but Peacock and McGuire had a huge influence for Leeds.