By Mark Lamport-Stokes

MARANA, Arizona (Reuters) - Rory McIlroy and Lee Westwood set up a mouth-watering duel in the last four of the WGC-Accenture Match Play Championship when they each completed comfortable victories in the quarter-finals on Saturday.

Northern Ireland's world number two McIlroy never trailed before beating South Korean Bae Sang-moon 3&2 while third-ranked Westwood won 4&2 against fellow Briton Martin Laird at Dove Mountain's Ritz-Carlton Golf Club.

Either McIlroy or Westwood can depose Luke Donald as world number one by winning Sunday's final, adding extra spice to their semi-final encounter on Sunday morning.

Earlier on Saturday, Hunter Mahan crushed fellow American Matt Kuchar 6&5 in their quarter-final and will meet compatriot Mark Wilson, a 4&3 winner over Swede Peter Hanson.

Mahan birdied four of his last six holes on a breezy, sun-splashed day at Dove Mountain where the greens ran fast and firm to end his match at the par-five 13th.

"Today the course is playing tougher, I didn't make as many birdies," Mahan said after recording the largest margin of victory in the last eight at the event.

"Matt didn't play as well as he can or usually does. It made it easier to win a few holes with par. I played solid, didn't make any bogeys ... and I kept the pressure on him."


Mahan benefited from a series of errors by Kuchar, who dumped his tee shot into water at the par-three third and three-putted for bogeys at the fifth and seventh, to go four up.

Mahan then rolled in a 20-foot birdie putt at the par-four ninth to reach the turn five up.

Kuchar also bogeyed the par-four 10th after overshooting the green with his approach to trail by six before the match ended three holes later.

"It really came down to putting," a subdued Kuchar, the world number 14, said. "I think if I had putted well, I was in the match."

In the top match, Hanson bogeyed the opening hole to trail for the first time this week but he struck a superb approach to three feet for a birdie at the par-four ninth to reach the turn all square.

However, the Swede began to unravel as he bogeyed the 10th and 11th to go two down.

Rock-steady Wilson won the par-five 13th with a birdie, after deftly chipping from just short of the green to three feet, and the 14th, where Hanson bogeyed, to go four up.

"It was nice to hole about a 10-footer to win the match on 15 after he was in with birdie," Wilson said after reaching the semi-finals at the event for the first time.

(Reporting by Mark Lamport-Stokes; Editing by Gene Cherry)