CASARES, Spain -- Lee Westwood produced a blitz of birdies to defeat Anders Hansen 6 and 5 Thursday on the opening day of the World Match Play Championship, sending a message to two players trying to supplant him at No. 1.
Second-ranked Donald defeated Ryan Moore of the United States 4 and 3, while Kaymer edged Y.E. Yang of South Korea 2 and 1. Masters champion Charl Schwartzel was routed 6 and 5 by Miguel Angel Jimenez.
Westwood started with a bogey on the par-4 first hole but found his range with the putter to make six birdies between the fourth and 11th holes, overwhelming his Danish opponent.
"I hit it close all through that run of birdies," said Westwood, who is bidding for a third straight tournament victory after wins in Indonesia and South Korea.
"If you get on a winning run where you're in contention a lot and finishing it off, that works wonders for your confidence and you start getting in that habit. But I've seen enough ups and downs in golf to know that you don't take good play for granted. You have to work constantly at it."
Westwood didn't compete in last week's Players Championship at the TPC Sawgrass. It's considered by some as the fifth major, but Westwood wanted to stay fresh not only for the World Match Play but also a string of tournaments this summer.
"I feel fresh, feel good coming into this week, which is tough and demanding," said Westwood, who credits his stamina and strength to a strict fitness regime he began four years ago. "I had such a busy time in the first part of the year, I was going to need a break at some stage to just sit down and do nothing and recharge."
Westwood plays Australia's Aaron Baddeley on Friday in his second group match.
Donald, who beat Kaymer to win the Accenture World Match Play in Arizona in February, again showed his pedigree in the one-on-one format in Group B.
Birdies at the third, fourth and seventh holes put Donald 3 up, and two more at No. 14 and No. 15 ended the challenge of the only American player in the 24-man field.
"I haven't had too many disappointments in match play. I enjoy the format and I've been very successful in it," said Donald, who has finished in the top 10 in 13 of his last 14 events. "I continued the form I've been playing the last few months. I'd put it in the solid category."
Donald needs to win the tournament and hope Westwood doesn't make the final if he is to move to No. 1 for the first time. Kaymer, meanwhile, requires Westwood to be eliminated before the semifinals to return to the top of the rankings.
Kaymer was 2 down to Yang by the 11th but won the next four holes.
Schwartzel is trying to emulate his fellow South Africans Gary Player and Ernie Els, who won the tournament 12 times between them. But he bogeyed the opening two holes and failed to match the consistency of Jimenez, who was born in nearby Malaga but played this course for the first time.
Jimenez didn't drop a shot for the entire round.
"I just kept playing solid -- pars, pars, birdies, pars. That's the game today," said Jimenez, who went 3 up after five holes and never looked back.
Schwartzel must avoid defeat in his second Group G match -- against Johan Edfors on Friday -- to have a chance of qualifying for the knockout stages this weekend.
Under the tournament's new format, two players from each of the eight three-man groups go through to the last 16.
Elsewhere, No. 5-ranked Graeme McDowell, the U.S. Open champion, defeated British Open champion Louis Oosthuizen 3 and 1 and fellow Northern Irish player Rory McIlroy also won, beating Retief Goosen by 1 hole.