Rory McIlroy and Lee Westwood, each seeking a title to become World No. 1, advanced to a semi-final showdown at the World Golf Championships Accenture Match Play Championship on Saturday.
World No. 2 McIlroy of Northern Ireland defeated South Korea's Bae Sang-Moon 3 and 2 while Englishman Westwood, ranked third, defeated Scotland's Martin Laird 4 and 2 to set up a high-stakes semi-final at the $8.5 million event.
"It will be a great match," Westwood said. "I hope we both play well and make lots of birdies."
Either Westwood, a former World No. 1, or McIlroy, trying to achieve the mark for the first time, would replace England's Luke Donald as the World No. 1 if he wins Sunday's 18-hole final.
But before one of them gets the chance to face either Hunter Mahan or Mark Wilson in Sunday's afternoon final, he must conquer the other in a morning semi-final.
"It's the match I wanted and the match everyone else wanted," said McIlroy, who at 22 would become the youngest WGC Match Play champion.
Not since 2004 have two of the four top seeds reached the semi-finals of the event and not since Tiger Woods and Davis Love met in 2000 have two top seeds met in a semi-final.
Mahan beat US compatriot Matt Kuchar 6 and 5 without losing a hole and Wilson ousted Sweden's Peter Hanson 4 and 3 in other quarter-finals to set up an all-American semi-final and ensure the event's first US finalist since Tiger Woods won in 2008.
"Hunter has made a ton of birdies this week," Wilson said. "I've got to focus on hitting the green and making that par. I'm not going to change anything about the way I'm playing."
Bae, 25, beat McIlroy in a head-to-head showdown in the final round of the South Korean Open three years ago, but the 44th-ranked Bae had never played in a WGC or match-play event until this week.
McIlroy seized the lead with a birdie at the first hole but found water off the tee at the par-3 third and took a bogey that sqaured the match.
Bae sank a long birdie putt at the fourth, the longest par-4 hole in PGA history at 536 yards, but McIlroy kept the match leve with a round-the-cup effort.
McIlroy sank a five-foot birdie putt at the eighth to regain a 1-up edge but went well right off the 10th tee and landed under a desert bush, forcing him to take an unplayable lie on the way to a bogey that squared the match.
McIlroy responded with a birdie to win the par-5 11th, then Bae found a bunker off the 13th tee while McIlroy blasted inches from the cup out of a greenside bunker to seize a 2-up advantage.
A tap-in birdie at the 15th put McIlroy 3-up with three holes to play and he halved the last to secure the triumph.
"I felt like I hit some really good shots," McIlroy said. "I felt like everything was pretty solid. I played really well out there."
Westwood, who had been No. 1 until being overtaken by Donald last year, had not trailed in a match this week until Laird opened with a five-foot birdie putt.
"He started how I wanted to start, fast and strong," Westwood said of Laird. "I could have been 3-down after three.
But Westwood sank a 13-foot par putt at the sixth to square the match, then birdied to win the seventh and moved 2-up at the turn when Laird bogeyed the ninth.
Westwood moved 3-up when Laird bogeyed 10, but the Englishman missed a five-foot par putt and Laird tapped in to win the 11th.
Sinking a tense birdie putt from six feet allowed Westwood to halve the 13th and Laird found a greenside bunker to prompt a concession at the 14th that put Westwood 3-up. After they halved 15, Laird fell at the 16th.
Hanson had not trailed in any match this week, but promptly fell behind Wilson with a bogey at the opening hole.
A bogey by Wilson at the sixth squared the match. Wilson birdied the eighth to briefly reclaim the lead, only to have Hanson sink a five-foot birdie at the ninth.
Hanson began the back nine with back-to-back bogeys to fall 2-down and Wilson sank a three-foot birdie at 13 to move 3-up. After another bogey by Hanson put Wilson 4-up Wilson birdied 15 to halve the hole and seal the victory.