Lee Westwood shakes hands with Rory McIlroy on the 17th following his 3 and 1 defeat. Picture by Fran Caffrey/www.golffile.ieRory McIlroy confessed that his massive desire to beat Lee Westwood ultimately cost him the WGC-Accenture Match Play and the chance to become Ireland’s first world No 1 last night.

The Ulsterman admitted that he became too emotionally invested in beating his former ISM stablemate in the semi-finals and was mentally out for the count in the decider, going down 2 and 1 to Hunter Mahan after a slow start and a poor run around the turn.

“No disrespect to the other two guys in the other semifinals, but it was almost my final in a way,” McIlroy said of his epic, 3 and 1 win over Westwood.  “That was the one I wanted all week and I got.  And that’s what I got myself up for.”

McIlroy came back from three down after four holes to cruise to a comfortable win over Westwood in a thrilling dawn duel.

But the cost was simply too great as he fell four down to Mahan after 10 holes before mounting a late, but ultimately fruitless comeback that saw him play his last seven holes in five under par.

“Maybe mentally and emotionally it did take a little bit out of me,” McIlroy said.  “But it still doesn’t take away from the fact that Hunter played very, very solid golf.”

Mahan’s second World Golf Championship victory earned him a cheque for $1.4m and a move from 22nd to ninth in the world.

And while McIlroy remains second in the rankings behind Luke Donald, he knows that his rise to world No 1 is only a matter of time.

“I’ve got two events coming up, the Honda and Doral, you know, I just you want to keep putting good results up on the board, try to get a few wins,” he said after a run that has seen him win twice and rack up another eight top-five finishes in his last 11 starts.   

“And if I can do that then ultimately getting to the top of the World Rankings is hopefully inevitable, if I keep playing golf the way I am at the minute.”

The final was all square after four holes as the finalists bookended birdies at the second and third with bogeys at the first and fourth.

McIlroy was especially gutted to miss a five foot par putt for a win at the first but  it was soon apparent that he had left his best stuff on the course in his epic morning win.

After halves in par at the fifth, Mahan claimed the 158-yard sixth when he hit a glorious tee shot to just 18 inches.

It was the start of a forgettable run of holes for the Irish star, who made some questionable course management mistakes to allow Mahan to comfortably dominate the match.

The Ulsterman lost the seventh to a bogey after following Mahan into a swale left of the green, gave away the par-five eighth with a hooked drive and another bogey and then lost the 10th to a brilliant Mahan birdie.

But he dug deep to make a match of it, chipping in for eagle for a win at the par-five 11th before a winning birdie at the 14th left him just two adrift with four to play.

In the end Mahan held on, matching McIlroy’s birdie at the 15th with solid pars at the 16th and 17th to close out the match 2 and 1.

McIlroy was still pleased to win his duel with Westwood 3 and 1, coming back from three down after just four holes to win in style.

A winning par at the fifth stopped Westwood in his tracks, McIlroy holed for winning birdies from 30 feet for at the sixth, 15 feet at the long eighth and eight feet at the ninth to turn one up.

A lucky ricochet off a cart path helped him halve the 11th and after burying a 25 footer for birdie at the 12th to go two up, he won the 13th in birdie to go three up.

Westwood hit back when he drove the 15th green and holed an 18 footer for eagle. But McIlroy got up and down from sand for a half at the 16th before being handed the 17th and victory when his rival came up short of the green with his approach and failed to chip and putt for par.

In the consolation match, Mark Wilson beat Westwood 1 up to claim a cheque for $600,000. Westwood had to settle for “just” $490,000 for his week’s work.