Donald had earlier produced a fine day of golf, demolishing quarter-final opponent Ryan Moore and last-four rival Martin Kuchar on his way to the final.

Victory at the Ritz-Carlton Golf Club would move the Briton up to number three in the world.

Kaymer is already assured of replacing Lee Westwood as number one but the 26-year-old, who defeated Miguel Angel Jimenez in his last-eight tie, is more worried about taking on Ryder Cup team-mate Donald in the final.

“It has taken me only five years to get to number one,” he said. “For myself, my family and the people I work with it’s a great achievement.

“I was not thinking about the number one spot (against Watson) as I was sure I would get the opportunity again over the next few weeks, I just wanted to win the match.

“He made a great birdie at 17, you can’t do anything about that, but it worked out fine. Luke is probably one of the best match play players in the world, we get along well but because it’s a final it will add more pressure.“

Watson had earlier come from five down to beat JB Holmes in a play-off at the quarter-final stage but he gave himself too much to do in a scrappy last-four encounter.

The pair were all square through 12 before Kaymer went one up at 13.

Watson hit back as his opponent could only bogey the 14th, but the American was then crucially inaccurate with his tee shots at 15 and 16, allowing a birdie and a par to put Kaymer two up with two to play.

Watson then produced a brilliant birdie three at the 17th to keep the tie alive, but Kaymer held his nerve to hole the putt that secured him a minimum of a half at the last.

Donald had impressed with a 5&4 win over Moore, before going on get the better of Kuchar 6&5.

He was six-up at the turn having birdied all but two of the first nine holes and, after going seven-up on the 10th, could even afford to drop two straight holes before an excellent approach shot on the 13th allowed him to pick up another birdie and take the match.

“It was good,” Donald, who only played 27 holes in the day, told Sky Sports.

“I didn’t leave anything out there and I was pretty dominant. I was able to keep my opponents at bay. On a long day like this it was nice to get done early in both matches.

“I didn’t know I could go to number three in the world, but that would be amazing. I’ve been playing consistently, but it’s been a while since I’ve won over here (in America).“

Kuchar added of his opponent’s performance: “There’s no escaping Luke Donald. I played decent golf but he just tore me up.”