England's Luke Donald plays a shot from the rough on the 7th fairway during his final round of the PGA Championship in Wentworth, England, on Sunday. Inset: Donald celebrates with his wife Diane and daughter Elle.

Luke Donald replaced Lee Westwood as world No. 1 after beating his fellow Briton in a titanic final-day shootout that went to a PGA Championship playoff at Wentworth, England, on Sunday.

After the pair had finished 72 holes tied on 278 - six under par - Donald produced a birdie four at the first extra hole to pick up the first prize of 750,000 euros (US$1.07 million).

Donald, who started the week ranked second in the world, struck a majestic third with his wedge at the 18th and the ball spectacularly spun back to finish eight feet from the hole to loud cries from the West Course crowd of 'Luke, Luke, Luke'.

Westwood played an almost replica wedge shot to his Ryder Cup foursomes partner but his ball unluckily spun back into the moat at the front of the green and his hopes of remaining at the top of the rankings were effectively ruined.

"This feels great," Donald told reporters. "I've been a runner-up a few times in my career and a few times this year but to finally come through in one of the biggest tournaments in the world and after going head to head with Lee is a bit special.

"It doesn't get much better than that. I'm not sure it will ever happen again when the No. 1 and No. 2 in the world are in a playoff not only for a win but to take over at the top of the rankings.

"A bit of unique history has been made," he said.

Donald, who began the round in a tie for the lead with Italian teenager Matteo Manassero, struggled off the tee all day but managed to scramble his way to a one-under 70 on another tough day for scoring at the European Tour's flagship event.

Westwood, playing in the match ahead of his fellow Englishman, notched five birdies in a 68 and had the chance to capture the coveted trophy for the first time at the 18th attempt when he missed a six-foot putt at the 72nd hole.

Britain's Simon Dyson (69) took third place on 280 and Australian Marcus Fraser, Frenchman Raphael Jacquelin and Ireland's Shane Lowry shared fourth spot on 282.

Donald said his first PGA Championship victory was all the more important because of the quality of the field assembled here this week.

"Winning is always the priority but being world number one is a great honor," said the 33-year-old, who has recorded top-10 finishes in all but one of the 10 events he has played on the European and US circuits this season. "This is a big field. To come here and win when seven of the top nine in the world are playing is special," added Donald.

In Irving, Texas, Keegan Bradley won the Byron Nelson Championship for his first PGA Tour victory, parring the first hole of a playoff with Ryan Palmer on Sunday.

Bradley, the nephew of LPGA Tour great Pat Bradley, sank a 2-foot par putt at the 419-yard 18th hole in the playoff.

Palmer's approach went into the water and he made a bogey with a 13-foot putt.