Rory McIlroy was doubly satisfied after he claimed his first title in over a year with a dramatic one-shot victory at the Australian Open in Sydney.

The Northern Irishman birdied the 18th as Adam Scott bogeyed to bring to an end a miserable run of form.

His struggles this year are in sharp contrast to his successes in 2012 when he won five times around the world, including a second major title when he won the US PGA Championship by eight shots.

The former world number one began the day four shots behind Australian Scott but a round of 66 - highlighted by an eagle on the par-five seventh - powered him to victory as the reigning Masters champion faltered.

The overnight leader started and finished with bogeys as he carded a 71, letting slip what would have been his second Australian Open title and the triple crown of Australian golf - the Australian Masters, PGA and Open in the same season - achieved only once before by Robert Allenby in 2005.

Instead, McIlroy can celebrate a first tournament win since the DP World Tour Championship in Dubai last November.

John Senden, the 2006 champion, equalled McIlroy's six-under 66 to finish third at 11 under, thereby qualifying for the 2014 Open at Royal Liverpool.

Rhein Gibson and Bryden Macpherson both carded three-under 69s to finish in a share of fourth at nine under the card and also book their places at next year's British Open.

Jason Day posted a two-under 70 to finish at minus eight alongside New Zealander Mark Brown (69) and Matt Jones (72).

McIlroy, addressing a press conference after his win, said: "Since the end of September I have felt better with how my swing was, I felt that everything was coming together the way I wanted it to.

"It's been a frustrating year - I've worked hard and it's been a process, trying to get back to winning golf tournaments again.

"It was nice to be able to do it today."

He added on Channel Seven: "I wanted to get a win by the end of the season and finally I have been able to get one.

"But more satisfying than that is being able to take one of the best players in the world down the stretch and come out on top.

"Adam is a phenomenal golfer and a great competitor and probably even a better guy.

"I feel a bit sorry I was the one to ruin the triple crown for him and I am very happy and Adam should be very proud of himself - he is a credit to the game and a credit to this country.

"It is a very prestigious tournament - Jack Nicklaus, Gary Player, it seems like most of the greats of the game have won this tournament and I am honoured to put my name on that trophy."

"Since the end of September I have felt better with how my swing was, I felt that everything was coming together the way I wanted it to" - A victorious Rory McIlroy elaborates on his return to form

After the third-round tussle between the two failed to ignite, Sunday proved a much better encounter.

McIlroy followed up his eagle with a birdie from close range at the eighth to take a share of the lead.

Scott replied with a birdie on the ninth after an outstanding iron shot to regain the advantage, and after matching birdies on the 13th they headed to the final hole with Scott still up by one.

But the Australian put himself in trouble when he missed the green and then overhit a chip to leave himself with a long putt.

He could only bogey and that left McIlroy with the opportunity of rolling it in from five metres for the win.

Scott did not attempt to hide his devastation, saying: "I felt I did everything right.

"I was concerned how I was going to hit it today because I haven't been swinging the club very well for the last two weeks and I played really nicely, but the putter didn't behave itself. But that's the way golf is.

"I'm gutted, I felt I'd never have a better chance to win the Aussie Open.

"I just slightly misjudged a few putts, overplayed the break, missed a lot of putts on the high side and didn't quite have the eye in - and it always gets a lot trickier on the Sunday.

"But I just misjudged on the last and a player as good as Rory is going to take that opportunity."