Rory McIlroy might have remained sixth in the world but his dramatic final hole victory in the Emirates Australian Open in what was his last full start of a fraught season may well go down as one of the most significant of his career.

Four shots behind Masters champion Adam Scott (71) starting the day, he hunted down the Masters champion relentlessly, puling level after just eight holes before eventually snatching the title with a 15 foot birdie putt at the last after the Australian had overshot the green, chipped 60 feet past and made bogey.

The 24-year-old clenched both fists and gazed skyward as the winning putt dropped apologetically into the hole - something Scott failed to do all day as he missed six putts inside 12 feet, had including several short ones - for his first victory in more than a year.

"I am really pleased I was able to take on one of the best players in the world down the stretch and come out on top,” said McIlroy, whose gutsy, 12-foot par saver at the par-three 17th would prove crucial.

“He’s a phenomenal golfer, a great competitor and probably an even better guy. I feel a bit sorry that I’m the one to ruin the Triple Crown for him, but I’m happy for myself.”

It was no wonder, considering all that has gone on for him off the course this year. 

"I am really pleased I was able to take on one of the best players in the world down the stretch and come out on top,” said McIlroy, whose gutsy, 12-foot par saver at the par-three 17th would prove crucial.

“He’s a phenomenal golfer, a great competitor and probably an even better guy. I feel a bit sorry that I’m the one to ruin the Triple Crown for him, but I’m happy for myself.”

It was no wonder, considering all that has gone on for him off the course this year. 

“Since the end of September I’ve just felt in a better place, a better place mentally with some things off the course,” McIlroy said after his closing 66, clearly referring to the distraction of his split with his former management company and the legal cases that have gone with it.

“I definitely felt better with how my swing was. I just felt like everything was coming together the way I wanted it to. 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 again. It was nice to be able to do it today.”

His six under closing round, highligted by four birdies and a crucial eagle three at the seventh, gave him his 10th worldwide win as a professional. 

And while his two major victories hold pride of place ahead of his maiden wins in Europe and the US, this was affirmation for the Co Down man that his 2013 troubles were merely transitory and that he can go on to challenge the likes of Scott and world No 1 Tiger Woods for dominance in the game next season.

Reflecting on the many lows that came before today’s high, he said: “It’s frustrating because you know the level of golf that you can play and you’re just not able to play to that level. You’re working hard and you’re trying to find the reasons why and you think you’ve found it and then you haven’t. Then you try something else.

“It’s frustrating but I never lost belief, I never lost any of that. Golf’s a long career and I’m 24 years old. I get a little impatient at times and if I actually just took a step back and looked at the bigger picture, it hasn’t been too bad a year. It’s obviously been made a lot before today with the win.

“You know you have to go through the lows and I’m not saying it was a low this year, it’s not like I plummeted off the face of the earth. I’m still sixth in the world so it’s not too bad [LAUGHS]. It’s not the level that I feel like I can play to but I feel I’m getting back there, so it’s very pleasing.”

After a thrilling final day in front of massive crowds at Royal Sydney, the young Ulsterman finished on 18 under par to deny home hero Scott the triple crown and wash away the memories of the walk-off at the Honda Classic in March, the club-mangling incident at the US Open in June or the opening 79 in The Open at Muirfield and subsequent admission that he was playing “brain dead” golf.

While there have been occasional flashes of the brilliance that made his world No 1, the season has been a horrific one compared to the highs of 2012.

The green shoots of recovery began shortly after he announced the formation of his new management company in September (the 27th) and went on to finish second in the Korean Open.

After coming 27th in the BMW Masters in Shanghai, he was sixth in the WGC-HSBC CHampions and fifth in the DP World Tour Championship in Dubai before heading to Australia determined to grab a win that would give him some momentum heading into 2014.

“I always believed I could win,” said McIlroy, who admitted with a grin that he felt a tinge of guilt at denying Scott the Triple Crown in such circumstances at the last. 

“I think I knew what it meant [to Scott] and I guess just the way the tournament finished for him, having a one shot lead going down the last and having it taken away from you right at the very end, it’s tough. I’ve been in that position before. It’s not nice.

“But he’s had a phenomenal year. Masters champion, he won one of the FedEx Cup play off events. He came down here to Australia, won the Aussie PGA and then the Aussie Masters. Then World Cup last week and here. I think it’s a real credit to him that he came down and played all four weeks. 

“It would have been very easy to skip a couple and maybe play up in the Gold Coast and play the World Cup or even to play the World Cup I thought was very good.

“So to play four in a row is a credit to him to come down. I think he sort of knew what responsibility he had coming down as Masters champion; the first Australian to win a green jacket, and that’s just the sort of guy he is. He’s a true gentleman and what I said at the prize ceremony there, he’s a credit to the game but he’s also a credit to this country. I was just lucky to be able to come out on top today.”

Scott, who had 35 putts to 27 for McIlroy, was crestfallen to let the title slip at the death.

“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 (but) 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 — like it did the rest of the week — but I just misjudged into the last and a player as good as Rory is going to take that opportunity.

“It’s been a great year (but) obviously I didn’t want to finish like that. If I didn’t play any good the first few days and played great today and finished second I’d be pretty chuffed going into Christmas, so that’s how I should look at it.  I’ll get over this tonight and look forward to a few weeks rest and get ready to go next year.

“I just made an error on the last, misjudged the wind and hit too much club into the last, so that’s the way it goes. I felt I did everything right.

“I was concerned about 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 and the putter didn’t behave itself [LAUGHS]. So it’s just the way golf is. 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.

As for the final day, Australian observers insisted they hadn’t seen such big or enthusiastic crowds since Greg Norman was in his pomp or Jack Nickalus and Gary Player were winning Australian Opens.

Scot began bogey-birdie and by the time McIlroy birdied the fifth to get within three, it was clear that Scott’s putter was not firing on all cylinders.

An eagle three at the seventh, where he hit a towering approach to six feet as Scott could only make par, closed the gap to one. They were level at the next and while Scott brilliantly birdied the ninth to take a one-shot lead down the stretch, McIlroy would not go away.

He birdie the 13th as Scott’s eagle putt there rimmed the edge and stayed out. Then, after saving par from 12 feet at the 17th, he hit a wedge to 15 feet at the last after Scott’s approach have trickled over the back of the green and down a steep slope.

“I came here playing really well; a couple of really solid performances in China, Dubai and Korea. I knew that if I just kept that going, just try and get myself into contention.

“The really pleasing thing about my golf at the minute and about my golf, even all year, is any time I’ve got into contention and had a chance to win a tournament, I’ve always played well. 

“I’ve always played the best golf of the week and that’s something that’s really pleasing, to be able to play your best golf when you need to, when you’re under pressure. You can’t really ask anymore than that.”

Asked what he was thinking as the final putt dropped, McIlroy said: “I can’t believe I’ve won. I didn’t think it was going to unfold the way it did standing on the 18th tee. Adam must have just - I think he probably got a hard bounce for the second shot, I couldn’t quite see from where we were standing but it looked a pretty decent shot to me. 

“It might have just been a couple of yards too far and got a firm bounce through the green. I knew his chip was tricky. I thought worst case scenario I’d have a putt for a play off and then all of a sudden I have a putt for the win. I didn’t want to go extra holes.

“All I focused on, and the putt was my routine. I didn’t do anything differently. I didn’t think about whether it was to win the Australian Open or whether it was to get the first win this year. I hit it inside right and I hit a putt like I hit on a putting green any other day, and thankfully it went in.”

Australians John Senden, Rhein Gibson and Bryden Macpherson won the three places on offer for next year’s Open Championship at Royal Liverpool (Hoylake) through the first event in the new Open Qualifying Series

Emirates Australian Open, Royal Sydney,  Royal Sydney (Par 72, 6,938 yards)

270 - Rory McIlroy (N. Ireland) 69-65-70-66.

271 - Adam Scott (Australia) 62-70-68-71.

277 - *John Senden (Australia) 73-68-70-66.

279 - *Bryden Macpherson (Australia) 71-70-69-69, *Rhein Gibson (Australia) 71-70-69-69.

280 - Mark Brown (New Zealand) 75-70-66-69, Jason Day (Australia) 70-74-66-70, Matthew Jones (Australia) 68-68-72-72.

281 - Nathan Holman (Australia) 69-72-68-72.

282 - Adam Bland (Australia) 69-72-70-71, Ashley Hall (Australia) 71-71-68-72, Leigh McKechnie (Australia) 73-65-71-73, Max McCardle (Australia) 68-71-69-74.

283 - James Nitties (Australia) 70-71-74-68, Alistair Presnell (Australia) 67-71-74-71, David McKenzie (Australia) 66-75-71-71, Nick O’Hern (Australia) 70-72-70-71, Brady Watt (am, Australia) 68-70-73-72, Stuart Appleby (Australia) 75-67-67-74.

284 - Jamie Arnold (Australia) 72-68-74-70, Mahal Pearce (New Zealand) 72-71-71-70, Rod Pampling (Australia) 75-68-69-72, Richard Green (Australia) 69-66-73-76.

285 - Adam Crawford (Australia) 71-73-72-69, Matthew Griffin (Australia) 73-72-70-70, Ryan Ruffels (am, Australia) 77-67-68-73.

286 - Mathew Goggin (Australia) 70-73-75-68, Cameron Percy (Australia) 71-70-75-70, Steven Bowditch (Australia) 68-74-74-70, Michael Long (Australia) 72-71-72-71, Tim Wilkinson (New Zealand) 73-71-71-71, Kalem Richardson (Australia) 69-74-71-72, Geoff Ogilvy (Australia) 75-66-72-73, Aaron Baddeley (Australia) 67-74-72-73, Scott Arnold (Australia) 70-70-69-77.

287 - Jason Norris (Australia) 67-76-74-70, Peter Lonard (Australia) 72-71-73-71, Robert Allenby (Australia) 72-73-70-72.

288 - Matthew Millar (Australia) 70-73-75-70, Shih-chang Chan (Taiwan) 76-68-74-70, Stephen Allan (Australia) 75-70-73-70, Leigh Deagan (Australia) 71-73-73-71, Aron Price (Australia) 70-69-77-72, Ryan Yip (Canada) 65-75-74-74.

289 - Ryan Lynch (Australia) 73-72-73-71, Scott Strange (Australia) 71-73-73-72, John Young Kim (USA) 65-79-72-73, Jason Scrivener (Australia) 67-74-74-74, Michael Choi (Australia) 70-75-70-74, Anthony Murdaca (am, Australia) 71-74-66-78.

290 - Lucas Lee (Brazil) 70-75-79-66, Timothy Wood (Australia) 73-70-73-74, Tom Bond (Australia) 69-73-70-78.

291 - Ryan Haller (Australia) 74-69-76-72, Josh Younger (Australia) 69-69-79-74.

292 - Ming-hao Wang (China) 75-70-76-71, Anthony Brown (Australia) 68-74-78-72, Anthony Summers (Australia) 74-70-76-72.

293 - Steven Jones (Australia) 68-77-73-75.

294 - Marcus Cain (Australia) 71-73-77-73.

295 - Paul Spargo (Australia) 74-71-78-72, Steven Jeffress (Australia) 75-69-75-76.

296 - Matthew Guyatt (Australia) 71-74-75-76.

297 - Joon-woo Choi (Korea) 72-72-74-79.