Former Challenge Cup kings Wigan again have the scent of Wembley in their nostrils after seeing off Harlequins to advance to the semi-finals of the Carnegie Challenge Cup.

Tries from Chris Ashton and the in-form Pat Richards gave the Warriors a 12-0 half-time advantage and, although Steve Bannister pulled a score back at the start of the second period, Quins could not find another.

Instead, Mark Calderwood crossed again for Wigan and, after Trent Barrett's drop goal, a last-minute score from man-of-the-match Sean O'Loughlin sealed the misery for Quins, who had Jon Wells sent off after the break.

The Warriors were forced into a late team change when Shane Millard dropped out with a sore jaw and young hooker Mike McIlorum was promoted to the bench for his debut.

Quins were without Australian star Scott Hill but welcomed back former Wigan favourite Henry Paul, who starred for the Warriors during the tail end of their Wembley dominance.

Wigan got off to a dream start when, after an early Richards penalty goal, they crossed for a four-pointer with just four minutes gone.

O'Loughlin made the break down the right wing and, with Calderwood on his outside and Chris Ashton on his inside, he plumped for the young full-back who scored under the posts.

Richards added the extras for 8-0, but the Warriors were checked with the departure of form prop Iafeta Paleaaesina with what looked to be a knee injury shortly after although he later reappeared.

Wigan continued to look the team most likely to score, however, and extended their lead halfway through the half when Richards won the race to a clever kick from O'Loughlin, although the angle beat Richards' conversion attempt.

Quins' best chance of the opening half was when Chris Melling was pulled back for a forward pass after a lovely probing run from Danny Orr, and the former Wigan stand-off then forced a goalline drop-out from Calderwood with a stab into the corner.

Quins clearly needed something to kickstart them into the game, and they got it straight from the kick-off.

A hesitant Leuluai allowed the ball to bounce and, although Richards just prevented it going into touch, he was bundled over the whitewash for a Quins scrum, which led to Steve Bannister taking Orr's looping pass to score by the posts.

Paul Sykes converted for 12-6, but the Warriors scored their third try within three minutes when Calderwood was on the shoulder of a rampaging Phil Bailey, with Richards' conversion pushing the lead back out to 12 points.

The Londoners' cause was not helped shortly after when winger Wells was sent off for a high shot on youngster Darrell Goulding, referee Ben Thaler brandishing red on the advice of his touch judge.

The closest they came after that was when Sykes made a clean break down the right but, as his winger made the decision to come inside, the pass flew into touch.

And, when Barrett secured the victory with a drop-goal with just four minutes left, a sizeable chunk of the 10,835 - the highest Challenge Cup attendance this term - took it as their cue to depart.

Those that did leave early missed the icing on the cake from the immense O'Loughlin, whose punishing defence had done much to deter any hint of a Quins comeback.