Blue Monster eats Rory's Sunday lunch - remarkable Scott wins back-to-back
 Adam Scott. Picture: Getty Images

Adam Scott. Picture: Getty Images

Just when Rory McIlroy felt he’d found the secret, golf jumped up and punched him in the face in the final round of the WGC-Cadillac Championship last night.

A new putting method appeared to offer ultimate solution to his biggest weakness but at the precise moment he needed his majestic long game to work flawlessly, it quickly evaporated on a warm northeast Florida wind.

From three strokes ahead overnight, the world No 3 slumped to a two over 74, hitting just six fairways and nine greens as he finished tied for fourth with Danny Willett, two shots behind an extraordinarily resilient Adam Scott on 10 under par.

That McIlroy came to the last needing a birdie to force a possible playoff said more about the Blue Monster than his game. 

But as he drove into the palm trees, it was Scott, playing in the group in front, who got up and down from the hazard, holing a seven footer for par and a 69 to win his second WGC by a stroke from Bubba Watson on 12 under par.

"I didn’t make enough birdies,” a downcast McIlroy said. "I felt like my game was okay for the most part. I didn't take advantage of the holes I should have. I couldn’t birdie any of the par 5s and that's really what killed me today."

"It's frustrating because it's two out of the last three weeks. I was leading the golf tournament with 16 holes to play in Riviera. I was leading the golf tournament here  going into the back nine, and to not get the job done in either two of those instances is very frustrating.

"I wish I could have just done more on the front nine, but as I said, there’s plenty of positives to take from this week, and I'll get back at it next week in practice and hopefully get myself back into contention and do a better job of trying to finish the tournament off in Orlando.

“I’ve got two events left (Bay Hill and the WGC-Dell Match Play) to try to get that win before going to Augusta and I’m hopefully going to get it.”

How much of McIlroy's final round 74 was due to mental and how much was physical only he knows but Scott was understanding when he heard that McIlroy had struggled to get the ball close.

"I don't know how Rory played today, at all, but it is very hard to hit it in there close because the penalty is water," he said. "I found that trying too much and made two doubles. As the leader that's certainly not what you want. Maybe he didn't hole the putts he wanted to today and just didn't quite have it. It's hard going out there with the lead. It really is. It's harder than ever. A three-shot lead on a golf course like this is not a lot. It's a birdie to a double. It's one good shot to one bad shot. That's literally how fine a line it is."

The Australian (35) had started in calamitous fashion with two early double bogeys leaving him six strokes behind the Co Down man.

McIlroy had promised to give a display of controlled aggression, saying on the eve of battle, "defensive isn't my style."

A change of wind direction didn't help but he misfired so badly that any mental errors he made were exacerbated and he was left standing by several players including  a hugely impressive and clinical Scott, who won in back to back weeks for the first time since he captured the Australian PGA and Australian Masters in 2013.

The question before the final round was whether or not McIlroy’s putting would hold up under pressure as he led by three from Scott and playing partner Dustin Johnson, who crashed to a 79 that left him tied 14th.

Instead, his putting became nothing more than an afterthought as he went to the turn in two over par and dropped another shot at the 13th to fall two shots off the pace.

The fact that McIlroy did not hit an approach shot inside 30 feet until the 12th, where he hit a 40 yard pitch to nine feet and missed the birdie putt, said it all about his long game on a day of testing, 20 mph gusts.

Having played the 12 par-fives in nine under par heading into the final round, McIlroy couldn’t buy a birdie four last night and he had to hole a seven footer just to save par at the downwind eighth after his approach ended up in the lake left of the green.

The Holywood star’s first mistake came at the seventh, where he overshot the green and left himself an impossible chip, ending a run of 40 consecutive holes without a bogey.

When Watson dropped a 20 yard putt for eagle at the eighth, the Ulsterman’s lead was down to one on 11 under and he was the only player at the top of the leaderboard without a birdie on his card.

A bunkered tee shot at the par-three ninth led to a bogey, leaving him in a four way tie for the lead with Willett, Mickelson and Watson.

While Watson soon took control, drilling hime a 25 footer at the 12th for birdie to lead by one from McIlroy, Scott scorched up the leaderboard with birdies at the 10th, 11th, 12th and 14th.

McIlroy made his first birdie of the day at the drivable 16th, smashing out to seven feet and holing the putt to get to within two of Scott on 10 under.

He had a chance to birdie the 17th and get within one but missed as Scott put himself behind a palm off the tee at the 18th and almost cut his approach into the lake, staying up miraculously.