Molinari lines up the birdie putt on 3 that kept his lead at two strokes. [China.org.cn]

Molinari, meanwhile, had opted for caution. He laid up in front of the green, then played a lovely pitch to no more than three feet. Westwood had to do at least as well, but from his horrible lie he could not even find the green. He tried his best to hole his next, and almost succeeded, but in the end it was par. Molinari sank his birdie putt and the margin was two strokes with two to play.

Both players parred 17, and there was one final act of drama. On the par-5 18th, Molinari again opted for caution, laying up with his second shot. Westwood found the green in two. Molinari's approaching wedge was erratic – he was further from the hole in three than Westwood was in two, and in a similar location. He putted first, and didn't make it. Westwood knew he had an eagle putt to force a play-off, but it was longish, and very tricky down the slope of the green towards a flag at the front by the water. He couldn't make it either, and his birdie to Molinari's par wasn't quite enough.

"It feels great just now," said the winner. "I think it was a great day of golf for everyone – for the two of us, me and Lee that were playing and for everybody who was watching. I'm obviously amazed the way I played and you know to have the No. 1 player in the world trailing you by just one shot – it's not easy. I just played really well, and behaved really well on the golf course. So it just feels fantastic now."

At the start of the day England's Luke Donald, playing alongside Molinari and Westwood, was the only man who might have harboured hopes of catching the two leaders at the start of the day. But in order to do that he needed to get out of the traps fast. He had played extremely well to keep in touch on the third day, but the shots just wouldn't come right from the start of the final round. Bogeys on 4, 6 and 9 put paid to his challenge.

Instead, it was Molinari who threw down the gauntlet with birdies at 2 and 3. Westwood was able to keep the margin at two strokes with a birdie of his own at the par-5 third, and when Molinari birdied the 5th and then the par-5 8th again Westwood responded. But that meant it was still two strokes at the turn.

Westwood hit back immediately on 10, with another birdie to bring the margin back to a single stroke. And that's where it stayed until those dramatic last three holes.

Scotland's Richie Ramsay will be delighted with his joint third place. He beat Ernie Els on the day, and will take a lot of satisfaction and confidence from that into next week's tournament in Singapore. The other player in the trio, Ross Fisher of England, was the only man who managed to mount any kind of challenge.

While Donald was going backwards, Fisher birdied 2, 3 and 8 to move to 11-under and a clear third spot. But a disastrous sequence of seven dropped shots in seven holes from the 9th to the 15th saw him plunge down the field.

Tiger Woods restored some dignity with a last day 68 that saw him climb eleven places and finish in a tie for 6th – he made five birdies on the back nine. But he will still be unhappy with the composition of his round – seven birdies and three bogeys. He must be very concerned about the erratic nature of his play at the moment.

The title-holder going into the week, ever-smiling Phil Mickelson, had a disappointing day, with three bogeys on the outward nine. He fought back with four birdies on the return, but still finished with a 73 for +1 for the tournament, well down the field in 41st place. You would never have guessed from his demeanor after the round that he had played anything but his best.

And on that note there was one small fly in the ointment, one which ought to be mentioned. As Francesco Molinari pointed out, his behaviour on the course was terrific. It was a shame his behaviour afterwards didn't quite match up. He doesn't seem to smile much, and his natural expression appears to be something of a sulk. But yesterday he had won more than a million dollars on the day before his 28th birthday, and moved up about fifteen places into the top 20 in the world rankings. You would think that all this might have given him reasons to feel cheerful. So it was particularly disappointing that he refused to make time to sign a few autographs for some children who had waited for more than an hour while he went through the presentation and the following media interviews. I've never seen a tournament winner do that before.