SHANGHAI (AFP) - Germanys Martin Kaymer carded a sensational seven birdies on the back nine on Sunday to take the HSBC Champions title in Shanghai by three strokes over in-form Swede Fredrik Jacobson. The world number six Kaymer finished 20-under overall in the seven-million-dollar showpiece with his remarkable round of 63, capping off his day with a 15-foot birdie putt on the 18th. Jacobson had commanded the summit of the leaderboard since round two but the 54th ranked player fired three bogeys as Kaymer went three strokes clear with clinical green finishes including a blistering 30-footer on the 16th. Kaymer, who had nine birdies in all on the day, finished Asias flagship tournament on 268 at the Sheshan International course in Shanghai. It was an ok year, now it is a good one, said the understated 26-year-old German. I think that the winning putt was on the 17th today. I made a great birdie and I think that put me in a position where I felt that if I birdied again on the 18th, its all done, and even par would be enough, said Kaymer, who executed his plan clinically by birdying the last two holes. Kaymer began the year with his triumph at the Abu Dhabi HSBC Golf Championship but then saw his form dip until Sunday, when his game came together in spectacular fashion to snatch the win from Jacobson. Northern Irelands Graeme McDowell redeemed himself in part after his nightmare weekend at the Andalucia Masters last week. He carded five birdies in his five-under 67 to finish in third. Englands injury-recovering Paul Casey finished tied fourth alongside South African Charl Schwartzel and world number three and US Open champion Rory McIlroy. Northern Irish star McIlroy, who was shadowed inside the ropes by tennis star girlfriend Caroline Wozniacki throughout the tournament, saw his front nine rally to gain the lead peter out with two bogeys. Englands world number two Lee Westwood endured a miserable day at the office with bogeys galore and a spell looking for a wayward ball in a fir tree to finish tied 13th.