With his new mallet-style Ping putter leading the way, Mahan took a 3 up lead out of the front nine and was never headed despite a McIlroy mini comeback.
“He’s the best player in the world right now,” Mahan said. “I knew he’d made a charge, and he did.”
After coming from behind to defeat Lee Westwood in the semi-final earlier in the day, McIlroy was playing to be golf’s official world No.1 and that close match seemed to have taken a lot out of him.
“I didn’t get the best of starts,” McIlroy conceded. The 22-year-old Northern Irishman chipped in for a an eagle on the 11th to announce his back nine challenge but Mahan, who has been shown to be a little shaky when it has come to the crunch in the past, toughed it out.
It was Mahan’s second World Golf Championship win and the fourth win of his career. He is the first American to win the championship since Tiger Woods in 2008 and joins Woods, Phil Mickelson, Ernie Els, Geoff Ogilvy and Darren Clarke as multiple WGC title winners.
In the consolation match for third place America’s Mark Wilson defeated Westwood 1 UP.
The highest ranked Aussie was Queenslander John Senden, who lost a close battle to one of the tournament’s surprise packets, South Korea’s Sang-Moon Bae, 1 UP in the third round.