St Helens overcame the dismissal of Man of Steel Jamie Lyon to lay one hand on the engage Super League leaders' trophy after completing the double over their nearest rivals.

Leeds had a late try by Ashley Gibson disallowed as Saints shaded their Roses showdown to open up a six-point lead, with six matches left of the regular season.

But their first victory at Headingley for four years was marred by the sending-off of Lyon 12 minutes from the end for a late and high tackle on Leeds' Rob Burrow.

Thunder and lightning outside the ground was matched by the stormy atmosphere on the pitch for a pulsating match watched by a 17,700 crowd, the Rhinos' fifth sell-out of the year.

Leeds sprung a selection surprise, rookie scrum-half Jordan Tansey replacing Lee Smith at full-back following their surprise defeat at Castleford - and the youngster stood up well to the test.

Saints were hit by the late withdrawal of scrum-half Sean Long, who failed to recover from a leg injury, but he is expected to play in next Saturday's Challenge Cup semi-final against Hull KR.

The Rhinos made all the early running and took the lead on 14 minutes when Great Britain second rower Gareth Ellis took Danny McGuire's well-timed pass to go through a gap and hold off the challenge of Saints full-back Paul Wellens on a 30-metre run to the line.

Captain

Kevin Sinfield's successful conversion enabled him to register his 500th Super League goal and put his side 6-0 in front.

But Saints drew level four minutes later when substitute forward Maurie Fa'asavalu drove for the line from acting half-back, and video referee Ian Ollerton gave him the benefit of the doubt in awarding the try.

Fa'asavalu then broke clear to get second rower Lee Gilmour charging for the line, but this time referee Ashley Klein did not need to refer the incident since the Saints man was clearly held up on his back.

It proved the defining moment of the first half.

Saints were still pressing when stand-off Leon Pryce's pass to Vinnie Anderson went to ground, and Leeds veteran centre Keith Senior picked up and raced 80 metres for a glorious try.

Sinfield kicked his second conversion and added a penalty three minutes from half-time, after Willie Talau (St Helens) and Chev Walker (Leeds) were both sent to the sin bin for coming to blows.

The game was once more on a knife-edge, though, after Saints added a second try in the final move of the half.

When Gilmour took Wellens' pass he was a full 12 metres from the line, but a sudden downpour had softened the lush turf and enabled the second rower to slide over the line in one movement.

Lyon's second conversion, this time from the touchline, brought the visitors back to within two points.

As the rain continued to fall, handling became more precarious. But the increased error rate served to heighten the excitement and tension.

Wellens was kept on his toes by the kicking game of Sinfield, while St Helens' replacement scrum-half James Roby came more into the game in the second half.

The decisive moment came on 64 minutes when Cunningham brought Gilmour on to his perfectly-timed pass to race into a gap - and although he lost his footing on the now treacherous surface, he quickly got to his feet to cross for his second try.

Lyon's third goal made it 18-14, but it was to be his last contribution before he was shown the red card for the late blow to Burrow.

Leeds thought they had at least snatched a point when winger Gibson went over at the corner five minutes from the end, but he was brought back for a forward pass.