Scotland's Martin Laird came up against a man in form yesterday, and went down 4&2 to Lee Westwood in the quarter-finals of the Accenture Match Play Championship in Tucson.

In the semi-finals Westwood will now go head-to-head with Rory McIlroy who overcame Korean Bae Sang-moon by the same score, and the reward for the winner at the end of the day could be the world No 1 spot.

Americans Hunter Mahan and Mark Wilson meet in the other semi-final, Mahan demolishing compatriot Matt Kuchar 6&5 and Wilson maintaining his record of not needing to play the last two holes by seeing off Swede Peter Hanson 4&3.

It was at this event last year that Westwood lost the No 1 spot to German Martin Kaymer. He grabbed it back with two wins in Asia in April, but has been behind Luke Donald ever since losing a play-off to him in the BMW PGA Championship at Wentworth a month later.

Never previously beyond the second round at the Match Play in 11 previous appearances, the 38-year-old from Worksop has been superbly impressive in knocking out Nicolas Colsaerts, Robert Karlsson, Nick Watney and then Laird.

The Arizona-based Glaswegian became the first player to take the lead against Westwood when he rolled in a six-foot birdie putt on the first, but Laird, who came into the week ranked 40th, bogeyed the sixth, seventh, ninth and 10th to be in deep trouble at three down.

Westwood handed one back by three-putting the long next after finding the green in two, but Laird's three attempts to get out of a bunker on the 14th gave him a mountain to climb and Westwood was in no mood to let him back in.

Westwood said of taking on McIlroy: "We've played a lot together. It will be a good match – I hope it will be a great match, that we both play well and make a lot of birdies."

McIlroy added: "I'm looking forward to it. It's obviously what I wanted going out today and I think it's the match everybody wants to see.

"I know I will need to play my best. It's going to be a big day, but I can't get too far ahead of myself. I've just got to concentrate on beating Lee Westwood and that's a tough enough task in itself."

McIlroy began in style with a birdie, but was in the lake at the third and with eight to play was again all square. It was then he showed his class, making birdies at the 11th and 13th – both par fives – and another on the driveable 15th when he chipped to two feet.

"For the most part I felt I played pretty well," the US Open champion said. "I hit a couple of loose drives, but apart from that I thought it was some of my best golf of the week. You really have to try to control your ball flight and pick your spots on the greens."

Mahan admitted he was surprised at how poorly Kuchar played given "the level of game he has", while the short-hitting Wilson commented: "They talk about it being a bomber's course, but you have to hit it straight too."