Mountain's Ritz-Carlton Golf Club but he lost the 15th to a birdie and both 16 and 17 to pars.
heart of the green to set up a regulation par and book his place in the last four.
"That puts stress when you are four up and four to go, and then all of a sudden you make a couple of
mistakes," Kaymer told reporters.
"But the way I played golf, at least the first 14 holes, was very good. I made two good long putts for
birdie. And I just feel good about my game."
Kaymer, who would become world number one for the first time if he reaches Sunday's 18-hole final,
will face American left-hander Bubba Watson in Saturday afternoon's semi-finals.
Watson conjured a spectacular escape to beat compatriot J.B. Holmes after 19 gripping holes in a
match-up between two of the game's biggest hitters.
Holmes, helped by a devastating display of power off the tee over the front nine, had been five up on
Watson after 10 holes before losing control.
LEVELED MATCH
Watson clawed his way back to one down after 15 holes before leveling the match at the 18th,
where Holmes bogeyed after missing the fairway off the tee and ending up under a bush with his
second shot.
Holmes then bogeyed the 19th hole, the par-four 10th, after taking an unplayable lie in desert scrub
off the tee and hitting his third from the 18th fairway. Watson sealed victory by coolly sinking a par
putt from just under four feet.
Britain's Luke Donald became the first player to reach the last four at Dove Mountain with a
commanding 5&4 victory over American Ryan Moore.
The Englishman produced sparkling form on a chilly, overcast morning, compiling seven birdies and just
one bogey to overpower his opponent.
Donald chipped in for an unlikely birdie from behind the green at the par-three sixth to go four up by
the turn and sank a nine-footer at the par-four 14th to seal the win.
"I played nicely," world number nine Donald said greenside. "I got off to a great start, got up early,
and that chip-in on six was a big turning point. It looked like a tough up-and-down.
"The short game has been good, and it has been tidy. I haven't given up too many holes this week. And I've made a bunch of birdies, too."
Donald, who would climb to a career-high third in the world rankings by winning this week's final, will next meet American Matt Kuchar, who beat South Korean Yang Yong-eun 2&1.
