Ian Poulter closed with his second straight 65 on Sunday and that helped him come from behind and win the WGC - HSBC Champions by two strokes.

Poulter, who won his second WGC title, finished at 21-under-par 267. His total of 267 bested the previous record of 268, which David Howell set in 2005 and Martin Kaymer matched last year.

"It has been an amazing kind of six weeks I guess with the Ryder Cup and coming here in good spirits. I played well last week and I took a lot from there. I knew that I had just done the right things this week, I'd be right there in the end," said Poulter, who went 4-0 to help the European team keep the Ryder Cup.

"It was a special day. I said on Wednesday that I thought there was a 10-under par round out there and we saw that yesterday. So I knew there was a good round of golf in me."

Jason Dufner fired an 8-under 64 to jump into a share of second place at minus-19. He was joined there by his Ryder Cup teammate Phil Mickelson (68), British Open champion Ernie Els (67) and Scott Piercy (65).

Third-round co-leaders Lee Westwood and Louis Oosthuizen both closed with even-par 72s to share sixth place at 18-under-par 270.

Adam Scott shot 67 on Sunday and ended alone in eighth at minus-17, while last year's champion, Kaymer, was one stroke further back after a final-round 68 on the Olazabal Course at Mission Hills.

In an event that had players making big runs each day, Poulter drained six birdies in a 9-hole stretch Sunday to soar to the top of the leaderboard.

The Englishman converted back-to-back birdie chances at the second and third. After three straight pars, he caught fire.

Poulter birdied the par-5 seventh and made it two in a row with a birdie on the eighth. His birdie on the 10th gave him a piece of the lead.

The 2010 WGC - Accenture Match Play champion knocked in a 3-footer for birdie at 11 to move into the lead at 20-under.

Poulter stretched his lead to two with a 5-foot birdie effort at 14. On the par-5 15th, his second shot found a greenside bunker. Poulter blasted to five feet and poured in the birdie try to get to 22-under, where he was three clear of the field.

Down the stretch, Poulter hung on. He 2-putted for par on 16 from about 30 feet out. He missed the green on the par-3 17th and that led to his only bogey of the day.

"I did know the situation. On 17, anywhere left of the pin is fine with 7- iron. So I decided to push it down the right and leave myself a disastrous chip shot, and I made bogey," joked Poulter at the trophy presentation.

Poulter's lead was down to one. He saved par from a bunker at the last to win by two as his closest competitors stumbled down the stretch.

"To sign off with a win for me, I feel confident when I'm in good form, and I've been in good form for a little while and it's just so nice to get my hands on another trophy," said Poulter, who has played all eight WGC - HSBC Champions.

Els, who played alongside Poulter, had five birdies in a 7-hole span from the third to the ninth. That put Els at 19-under, but that is where he ended as he played the back nine in even-par with a birdie, a bogey and seven pars.

Dufner and Piercy were in first at minus-19. Dufner had eight birdies and a bogey in an 11-hole stretch from the seventh. That burst got him to 19-under, but he parred the last to end there.

Piercy, in the group before Poulter, was 4-under through 14 holes. He drained three straight birdie chances from the 15th to gain a share of second place.

That left it all up to Mickelson, who was in the final pairing with Westwood and Oosthuizen. Mickelson spread five birdies over the first 11 holes. His birdie at No. 11 moved him into a share of the lead with Poulter at 20-under.

Mickelson missed the green with his approach at the 12th and that led to a bogey, which dropped him one back.

The 2-time winner of this event recovered that stroke with an up-and-down birdie on No. 15. Mickelson again fell two back as he bogeyed the 17th. Needing to hole his second shot at the last to force a playoff, Mickelson's approach stopped eight feet right of the hole. He 2-putted from there to share second place.

NOTES: Poulter earned $1.2 million for the win, which was his second on the PGA Tour and 12th on the European Tour ... The PGA Tour will be in Florida next week for the Children's Miracle Network Hospitals Classic, where last year's champion Luke Donald will not defend his title at the season-ending event ... The European Tour heads to Singapore for the Barclays Singapore Open, where Gonzalo Fernandez-Castano was a playoff winner last year.