Hunter Mahan shakes hands with Rory McIlroy of Northern Ireland after winning the championship match 2 and 1 on the 17th hole during the final round of the World Golf Championships-Accenture Match Play Championship at the Ritz-Carlton Golf Club on February 26, 2012 in Marana, Arizona.

American Hunter Mahan ended Rory McIlroy's bid to become world No. 1 for the first time with a 2&1 victory over the Northern Irishman in Sunday's final of the WGC-Accenture Match Play Championship in Marana, Arizona.

With McIlroy initially failing to replicate the stunning form he produced earlier in the day on the way to a 3&1 semifinal win over third-ranked Briton Lee Westwood, Mahan took advantage with a seven-birdie display.

The 29-year-old never trailed after going ahead at the par-three sixth, and he fended off a McIlroy fightback after the turn, ending the match with a comfortable two-putt par on the 17th green.

"Boy, it feels good," Mahan said after clinching his fourth PGA Tour title and a second World Golf Championships crown, having previously won the 2010 Bridgestone Invitational at Firestone.

"I didn't realize how difficult it is to win this week because it's six matches and you're playing against the best players in the world," said Mahan. "I played well from tee to green, putting to chipping to driving, irons, everything was there. And I needed everything to win. I'm very proud of how I played," added Mahan who totalled 35 birdies during the week from 96 holes.

World No. 2 McIlroy, like Mahan appearing in his first Match Play final, would have replaced Britain's Luke Donald as the game's leading player if had he claimed his first WGC crown.

"Deep down I wanted to postpone that crowning of the No. 1 player in the world for Rory," Mahan said with a grin. "But he'll be No. 1 eventually. I'm not worried about it, I'm sure he's not."

US Open champion McIlroy applauded Mahan's performance, but conceded that his hugely anticipated morning semifinal against Westwood had sapped some of his energy. "Maybe mentally and emotionally it did take a little bit out of me but it still doesn't take away from the fact that Hunter played very, very solid golf," the 22-year-old said.