(CNN) -- Rory McIlroy has never played in a World Match Play semifinal before, and he has never been ranked No. 1.
Lee Westwood lost his top spot at the World Golf Championship event in Arizona a year ago, and he wants it back. Before this week the Englishman had never made it past the second round of the 64-man tournament in 11 attempts.
Ideally they would be meeting in Sunday's 18-hole final in a showdown to see who will depose Luke Donald as golf's top dog, but instead they will have to clash in the semi.
The winner of that morning match will play either Hunter Mahan or Mark Wilson, with the U.S. assured of a shot at the trophy for the first time since Tiger Woods took it home for the third occasion in 2008.
"I think it's the match that most people wanted and definitely the match that I wanted," world No. 2 McIlroy told reporters after beating South Korea's Bae Sang-moon 3&2 in his quarterfinal on Saturday.
"I'm excited about tomorrow, it should be a lot of fun and very exciting for everyone involved.
"All I need to do is focus on the match tomorrow morning, and then I think the biggest task for both of us, me and Lee, is getting yourself so much up for the semifinal.
"You have to get yourself up for that again. So that will be the tough task because obviously both of us feel you've got to get past each other -- for Lee to get back to number one and me to get there for the first time.
"You have to put your all into that and then whoever wins tomorrow morning, you get yourself back up again to go back out tomorrow afternoon and win the whole thing."
While McIlroy has already won the U.S. Open at the age of 22, the 38-year-old Westwood is still waiting for his first major victory -- though he has topped the European Tour money list and ended Woods' record-breaking run at the top of the rankings in 2010.
"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," Westwood said of the clash with his European Ryder Cup teammate after his 4&2 victory over Scotland's Martin Laird.
"My priorities were to win major championships and win World Golf Championships because I haven't ever won any. I've been at No. 1 a couple of times. It would be a different way of thinking to me compared to Rory, who hasn't been No. 1. He may be thinking about it, but my main goal is to play well or play as well as I've been playing tomorrow morning and try and win that match."
Neither Mahan nor Wilson are ranked inside the top 20, but have both been in fine form at the Ritz-Carlton course this week.
World No. 22 Mahan went through after thrashing U.S. Ryder Cup teammate Matt Kuchar 6&5 in the shortest quarterfinal since the tournament started in 1999.
"Matt couldn't find the putter today, which is rare for him, because he's a great putter," Mahan said of his 14th-ranked opponent.
"I got lucky in that aspect. But I played solid, didn't make any bogeys and didn't give many holes -- and kept the pressure on him. That was nice to do."
Wilson, ranked 42nd and a three-time winner on the PGA Tour, cruised past Sweden's Peter Hanson 4&3, and has yet to play past the 16th hole this week.
"I don't think too many people picked me to win," said Wilson, who is looking to follow in the example of last year's winner Donald and his predecessor Ian Poulter -- none of the trio are long hitters.