His 17-under total of 271 over the Old Course at St. Andrews secured Kaymer’s third straight victory at a stroke-play event, following wins in the PGA Championship and KLM Dutch Open.
He is the first European player to achieve that feat since 1989 when Nick Faldo won the European PGA, British Masters and French Open titles. Tiger Woods had three straight victories in America in 2006.
Danny Willett of England finished second after he shot a 67 to reach 14 under.
With his $808,352 winning check, Kaymer increased his lead at the top of the Race to Dubai money list.
However, victory was not straightforward. He started the fourth round in Scotland two shots off the lead in a share of second place behind England’s John Parry.
It was only when he sank a giant 50-foot birdie putt on the famous 17th ‘Road Hole’ green that he broke clear of the field before clinching his win with a 10-foot birdie putt at the last.
“The 50-footer was a bit lucky,” Kaymer said. “Because from that length all I was really trying to do was get the ball close to the hole. But I am really enjoying my golf at the moment. And it’s not just three straight tournament wins, I was also on the winning side at the Ryder Cup so that’s four in a row.”
Parry, the young Englishman who won his first Tour event in Paris two weeks ago, had led by two shots going into the final round and still shared the lead with Kaymer when he sank a birdie putt on the 12th green.
However, a three putt at the next hole and then a penalty shot at the 14th when he drove into a gorse bush proved expensive. Parry eventually shot a level 72 and finished in third place.
It was another young Englishman Danny Willett who finished in the runner-up spot after he shot a 67 to reach 14 under.
Westwood would have ended Woods’ 278-week unbroken run at the top of the rankings by finishing first or second in Scotland.
The Englishman began his final round in a share of fifth place, only three shots behind Kaymer and Alvaro Quiros, who were sharing second spot overnight.
However, Westwood struggled to close the gap as he opened his final round with seven straight pars. He eventually shot a 73 to finish in a tie for 11th place.
He later withdrew from next week’s Portugal Masters with the ankle injury that has troubled him since July.