Germany's 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 timely round of 68, capping off his remarkable 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 Asia's 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. 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 Ireland's 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. England's injury-recovering Paul Casey finished tied fourth alongside South African Charl Schwartzel and world number three 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. England's world number two Lee Westwood endured a miserable day at the office with five bogeys and a spell looking for a wayward ball in a fir tree to finish tied 13th. Australian Adam Scott, whose caddy Steve Williams is at the centre of a race storm after comments about Tiger Woods, saw his challenge slip, finishing tied 12th after carding four bogeys. Scott is under pressure to sack Williams, who called Woods a "black arsehole" during a gala awards dinner on Friday night.