Kevin Penny try seals victory for Warrington at Leeds

The champions began the post Sinfield and Peacock era in optimistic fashion and they had their moments, fighting back from 6-0 down at half-time to lead 10-6.

But they were forced to re-shuffle after McGuire limped off with a knee injury on 31 minutes and winger Kevin Penny's 68th-minute try sealed a memorable win for the Wolves.

The victory was especially sweet for Australian half-back Chris Sandow, who made an inauspicious Super League debut at Headingley last August when Leeds romped to a 49-10 victory.

Leeds, who gave debuts to Brett Ferres and Keith Galloway, will not be too downhearted over the result but will be concerned over the fitness of their new skipper, with the World Club Challenge clash with North Queensland just a fortnight away.

The Rhinos looked anxious in the opening minutes, with Zak Hardaker, the reigning Man of Steel, and Liam Sutcliffe both producing handling errors, but the visitors were unable to make much of their early pressure.

As the champions settled into the game, Sutcliffe began to show some useful touches but he was held up over the line and then fumbled Adam Cuthbertson's pass with the line beckoning.

McGuire began hobbling on 29 minutes after taking a knock on his knee and limped off two minutes later to be replaced by youngster Jordan Lilley and Leeds troubles' worsened four minutes before the break when they conceded the first try of the game.

Sandow, who looked a completely different player to the one who played at Leeds six months earlier, opened the scoring, taking a pass from dummy half Brad Dwyer and wrong-footing Joel Moon to touch down.

Kurt Gidley, one of six debutants in the Wolves line-up, added the conversion to make it 6-0 but it was all square six minutes into the second half when prop Brad Singleton took Rob Burrow's pass and powered his way through a trio of defenders to touch down.

Hardaker added the goal and the Rhinos, with all the ball, went in front on 54 minutes when slick handling by Moon and Lilley created the space for England winger Ryan Hall to cross at the corner.

It had been all Leeds in the third quarter but when the Wolves managed to get their hands on the ball they were always a threat and they regained the lead on 67 minutes when makeshift centre Ben Currie collected Sandow's kick over the defence to send Penny in for their second try, which Gidley converted.

Currie then came to his side's rescue at the other end, pulling off a crucial tackle on Burrow when he seemed certain to score.

Leeds still had a chance to claim a share of the spoils when Lilley was obstructed as he followed his own grubber kick but Hardaker made a hash of his 30-metre penalty attempt.