By Nick Mulvenney
SYDNEY (Reuters) - Rory McIlroy claimed his first title of the year at the Australian Open by a single shot on Sunday after home favourite Adam Scott bogeyed the final hole to lose a tournament he had dominated since the opening day.
McIlroy, who swallowed up Scott's four-shot overnight lead in the first eight holes, nervelessly sank a 10-foot birdie putt at the 18th to finish on 18-under-par for the tournament with a final round seven-under 66.
Scott, who was seeking a rare "triple crown" of Australian titles after winning the PGA and Masters, missed a string of chances over the back nine to extend his lead and held just a single-shot advantage heading to the 72nd hole.
After firing his approach over the back of the green, the world number two overcooked his chip and sent the ball racing back past the hole before coming up short with a 40-foot par putt to give McIlroy a chance he grasped with both hands.
"It's hard not to feel some sort of guilt in the way that I won it," said two-times major champion McIlroy, who had been facing a first winless season since 2008.
"It's been a frustrating year but I've worked hard and it's been a process, trying to get back to winning golf tournaments, and it was nice to do that today."
In what emerged as a virtual matchplay contest, the pair played together over the final two rounds in front of packed galleries bathed in sunshine at the Royal Sydney Golf Club.
Scott, who had led from the first day of the tournament when he smashed the course record with a 10-under 62, finished with a 71 for second place on 17-under, six clear of John Senden (66) in third.
"I'm disappointed to make an error at the last and open the door for Rory," Scott said.
"I was kind of trying to keep it closed all day the best I could.
"Nothing was going my way on the greens today. I could have put this thing away I think early on if the putter was behaving how it should have..."
Bryden Mcpherson and Rhein Gibson, who both shot 69s to share fourth on nine-under, joined fellow Australian Senden in qualifying for next year's British Open at Hoylake.
Scott had started the day with a three-putt bogey at the first but reclaimed the shot when he smashed a superb second shot from the fairway with a wood to set up a birdie at the second.
McIlroy missed a birdie putt at the third but took a stroke out of Scott's lead at the fifth when a sublime approach shot set him up for a birdie.
Another long and accurate iron shot at the par-five seventh gave him an eagle and when Scott missed a four-foot birdie putt, the lead was reduced to just one stroke.
McIlroy drew level when he sank a six-foot putt to pick up a shot at the eighth before Scott lipped out with his shorter birdie putt at the same hole.
The roles were reversed at the ninth, where McIlroy missed his birdie putt by less than an inch while Scott drained a six-footer to reach the turn a shot in front at 17-under.
The pair parred the next four holes and both had eagle chances at the 13th, with Scott coming closest when his first putt shaved the cup before tapping in to match McIlroy's birdie.
Scott had another chance to go two ahead after McIlroy found a bunker at the par-five 16th but the Australian three-putted from the front of the green to match the Northern Irishman's par.
Scott wasted another opportunity to pad his advantage to a couple of shots at the par-three 17th when he lipped out again following a brilliant tee shot, leaving McIlroy to take full advantage in a dramatic conclusion to an absorbing contest.
"I just sort of stayed patient, I knew that anything can happen on this golf course, if you just hit it into a tricky spot like Adam did on 18," McIlroy added.
"Luckily I was just able to make that putt at the end when I needed it."
Scott said his final hole meltdown would not ruin a year in which he became the first Australian to win the U.S. Masters.
"It's just the way golf is," the 33-year-old said. "I'm gutted. I felt like I never had a better chance to win the Aussie Open but it was tight the whole back nine. Rory played so good."
(Editing by John O'Brien)