RORY McIlroy pulled off a win over Worksop’s Lee Westwood in Tucson.
The two stars met in the semi-finals of the Accenture Match Play Championship and Westwood, also with the chance to dethrone Luke Donald at the top of the rankings, went three-up after only four holes.
In 60 previous games during the week only two players had come back from such a deficit to go through, but McIlroy became the third with a thrilling display.
Westwood opened the door by bogeying the fifth and asking McIlroy to hole from two feet for par there appeared to fire Northern Ireland’s US Open champion into action.
He birdied three of the next four to turn one up and then had three more birdies in a row from the 11th. Westwood was able to match only the first of them, so found himself three down.
He then produced an 18-foot eagle putt after driving the green on the 343-yard 15th, but missed from similar range at the next and conceded defeat after bogeying the 17th.
Mahan, meanwhile, beat compatriot Mark Wilson 2&1 in a game overshadowed by the clash between the second and third seeds, also stablemates until McIlroy made what Westwood called a “bizarre decision” to leave in October.
Westwood and McIlroy insist there is no bad blood between them over the split.
Two months later, of course, McIlroy captured his first major title with a record score and by an eight-stroke margin.
Westwood remains without a major and without a world championship at 38.
McIlroy knew Mahan presented a tough hurdle in the 18-hole final, though. He has been a member of the last two American Ryder Cup teams and was the player, of course, whose defeat to Graeme McDowell at Celtic Manor two years ago gave Europe a nail-biting win.
He was also the only one of the four quarter-finalists who had a world championship to his name and he was never behind to Wilson.
Mahan did have one horrible shank at the fifth, but needed only a par to take the seventh and he matched Wilson’s two birdies at the start of the back nine.
Wilson got back to only one down when Mahan bogeyed the short 12th, but he was bunkered on the 15th and Mahan’s seven-footer took him two in front.
There did not seen to be anything said between Westwood and McIlroy at the end other than “well played” and “thanks”, but there no hiding how pleased McIlroy was.