Dustin Johnson's record-equalling final round meltdown has handed Justin Rose the WGC-HSBC Champions event in Shanghai.
Justin Rose roared back from an eight-stroke deficit to claim an astonishing two-shot win at the WGC-HSBC Champions event in Shanghai on Sunday after overnight leader Dustin Johnson threw away the tournament with a horror final round.
Eight strokes adrift of Johnson on the first tee, Englishman Rose fired a five-under 67, tearing up the back nine with five birdies at Sheshan Golf Club as the American gave up a six-stroke lead to finish runner-up with Henrik Stenson and Brooks Koepka.
Former US Open winner Rose finished the $US9.75 million ($A12.69m) event with a 14-under total of 274, a tap-in par on the par-five 18th enough to seal an ultimately comfortable win on a breezy day.
A hole behind, a shell-shocked Johnson had already come to grief with consecutive bogeys on the 15th and 16th, and he finished with a five-over 77 without a single birdie on his card.
"It's unbelievable," said Rose, whose chances looked to have disappeared when he bogeyed the eighth and ninth to reach the turn in level par.
"It's been a long time since I've won, or at least it feels like that.
"I've won every year since 2010, if you include the Olympics last year. I've left it late this year but it feels amazing.
"Obviously we all know the position DJ (Johnson) was in and I think today was the kind of day that the leader probably didn't want.
"You want a six-shot lead any time, but this is the kind of day where that kind of swing is possible.
"I shot five under in tough conditions and he had to play good golf to keep it around par today, and obviously he made a few mistakes.
"It was really tricky out there and obviously I played one of the best back nines I've played in forever.
"To shoot 31 on the back to come through, I saved my best till last."
Johnson, who won at Sheshan International in 2013, had recorded 22 birdies in the first three rounds but failed to manage a single one in the fourth.
"I hit a couple of really bad iron shots," he said.
"That was probably the key there on 14. I just chunked it. Same thing on 15, I just chunked it. That cost me two shots there.
"And then bogeying 16, that's just bad. So I just gave a few away."