Rory McIlroy has the momentum and the motivation heading into his semifinal match Sunday against Lee Westwood at the WGC-Accunture Match Play Tournament at the Dove Mountain course in Tucson.

“It’s the match that I wanted,” said McIlroy just after beating South Korea’s Sang Moon Bae, 3 and 2. “It’s the match that everyone else wanted.”

What everyone has wanted to see – especially including McIIroy – is who can be the No. 1 golfer in the world. It could come down to McIIroy or Westwood, currently No. 2 and No. 3, respectively, in the world.

Entering the tournament, England’s Luke Donald was the No. 1 but he went out in the first round. Since there are 76 points available for the tournament winner, either McIIroy, the 22-year-old from Northern Ireland, or English veteran Westwood could rise to the top.

McIIroy has been vocal all week. He wants. Westwood, who has been No. 1 twice briefly in his career, has played it down.

Westwood or McIIroy (pictured) has to win the tournament to ascend to No. 1. Whoever wins the morning semifinals would face the winner of the other semifinal, Hunter Mahan or Mark Wilson, in an 18-hole championship match Sunday afternoon.

McIlroy, who has told the media that the specter of No. 1 has been a motivating factor, never trailed in his match against Bae. In fact, McIlroy hasn’t trailed by more than 1 down in all four matches. He last trailed on the 10th hole of his first-round match.

At 22 years, 9 months and 22 days, the current U.S. Open champion would become the youngest to win the event, beating Tiger Woods, who was 27 years, 2 months and 2 days in 2003.

Westwood beat Scotland’s Martin Laird, 4 and 2. He came in without trailing in his three previous matches but went down to Laird on after the first hole. Laird them bogeyed four on the next five holes and Westwood coasted.

Westwood has yet to play the 18th hole in his four rounds this week. For the fourth straight year, an Englishman has reached the final four.

Unfortunately, NBC, which will carry the event, would have preferred a little tinkering of the schedule. Since the McIlroy-Westwood semifinal does not result in a new champion – or even a new No. 1 – it will be shown in the morning alongside the other All-American semifinal, Mahan against Wilson.

Seemingly, that would set up as an anticlimactic Sunday afternoon finale except for the fact that there will be one American in the finals. So the storyline will switch to beyond the quest for No. 1 to a more jingoistic approach. Chants of U.S.A. will echo through the hallows by every yahoo with a beverage. The match also will be used as extra motivation by Mahan or Wilson not only to win but to deny their opponent the No. 1 ranking.

Mahan, No. 22 in the world with three PGA career victories, has been a steady force throughout his time in the desert.. Saturday, he just smoked Matt Kuchar, who had been playing well. Mahan disposed of the world’s 14^th ranked player, 6 and 5, the widest margin in the tournament’s quarterfinals history. It was also Mahan’s widest margin in his 16 Match Play rounds.

He has played only 62 holes thus far through four rounds. After needing one extra hole to defeat Zach Johnson in round one, Mahan has won the next three rounds, 5 and 3 over Y.E. Yang and 4 and 3 over Steve Stricker. He made 20 birdies in his first three rounds (43 holes).

Wilson, ranked 42^nd in the world, has been like a stealth fighter – without the bombing. Most of the players here – certainly the final three semifinalists – are long-ball bombers, 320-yards-plus. Wilson, who insists that he’s not that much of a shorter hitter, still is tied for 159th on the PGA Tour this season. Mahan is 99^th.

Statistically, Wilson’s also not as skilled as a putter as Mahan, who ranks 59^th. Wilson ranks 73rd. But that doesn’t matter to the 5-foot-8, 145-pound Wilson. He’s very accurate, fourth best on the Tour. That means he doesn’t get in trouble as much as the other guys. He’s just sneaky good.

Wilson, who beat Sweden’s Peter Hanson Saturday, 4 and 3, has yet to play the final two holes in his four matches. Luke Donald (2011) and Tiger Woods (2003) are the only players to win the championship without playing the 18th hole. No player has won without playing the last two holes.

He is guaranteed to post his best finish, and first top 10, in the event in seven starts.

Here’s a look at the semifinals:

Mahan vs. Wilson: This is the eighth all-American semifinal in tournament history…Mahan would need to close Wilson on the 11th hole to tie Donald’s record for fewest holes played en route to a championship match (73)…Wilson has won five PGA Tour events, with three victories coming since the start of the 2011 season. A win would give him more PGA victories (four) than any other player in 2011-2012…only once before has Mahan lost to a player ranked lower than him, in 2010 when he was ranked No. 30 and lost in the first round to Charl Schwartzel (No. 35)…it guarantees that an American will be in the finals for the first time since 2008 (Tiger Woods vs. Stewart Cink).

McIlroy vs. Westwood: This marks only the second time in tournament history that two top seeds have squared off in the semifinals (2000 – No. 1 Tiger Woods versus No. 4 Davis Love III. Woods won, 5 and 4)…it also marks the first time two top seeds have made the final four since 2004 (Tiger Woods, Davis Love III)…Westwood has a 11-11 record in the tournament. McIIroy is 9-3.

Notes:

• Should Mahan or Wilson go on to win, it would mark the first time an American has won the first eight events on the PGA Tour since 2001 when Robert Allenby won the Northern Trust Open in the ninth event of the year. Before that, you have to go back to 1991 when Americans won the first 12 events.
• Mahan (29) and McIIroy (22) are two of the record 24 players under the age of 30 in the tournament. It’s the fourth time that two under-30 players have made the semifinals. If they both advance, it will mark the first under-30 final.
• If the championship match is tied after 18 holes, the extra holes will first, ninth, 10^th then 14 through 18.
• All four players are making their first appearance in the semifinals.
• Mahan has a 8-4 tournament record while Wilson is 5-4.