Arizona - Top seed Lee Westwood and No. 4 Phil Mickelson were among the surprise losers in the second round at the Accenture Match Play Championship on Thursday.
Westwood and Mickelson weren't the only big guns spiked as two-time runner-up Paul Casey, Northern Irishman Rory McIlroy and South African Ernie Els also were eliminated on a day of upsets at the Ritz-Carlton's Dove Mountain course.
This, following the first round elimination of third seed Tiger Woods, leaves the World Golf Championships event somewhat lacking in star power with 16 players still standing.
Only three of the top 10 seeds are still standing - No. 2 Martin Kaymer, No. 5 Graeme McDowell and No. 9 Luke Donald.
And German Kaymer barely survived, outlasting Englishman Justin Rose 1-up at the second extra hole.
Perhaps the most intriguing winner was Italian Matteo Manassero, at 17 the youngest player in the field.
Westwood did not play badly, but nonetheless continued his poor record in this event, having never advanced past the second round in 11 attempts.
He did not play badly, far from it, but in the end was edged 1-up by American Nick Watney.
"Nick shot five-under and I shot four-under, so that's pretty good golf," said Westwood, who wasn't entirely correct regarding their respective scores, but close enough.
"I think we were pretty even tee to green. Nick just holed a few more putts than me. I didn't putt particularly well, certainly not well enough but that's the way match play goes."
Watney, the 32nd seed, was relieved to win: "I played very well, especially at the start," he said.
"I got a couple up but he's not the world's No. 1 player for nothing and I knew he would come back.
"I know Lee's record and I knew he was going to be tough. It's very satisfying."
Mickelson, meanwhile, was no match for fellow American Rickie Fowler, an emphatic 6 and 5 winner.
"He hit a lot of great shots," said a philosophical Mickelson. "Certainly I got outplayed, that's obvious."
Fowler fell behind after three holes but that was the only hole he lost.
"I turned things around with two birdies and Phil left a couple of doors open that I took advantage of," Fowler said.
Manaserro was also a 1-up winner, fending off South African Charl Schwartzel.
"It's a big sense of achievement for me," said Manassero, whose lack of length off the tee has not hindered him so far.
"I'm really confident because I'm driving the ball well, hitting the irons well.
"If I make a few more putts, it's going to be absolutely perfect. I'm really confident on my game, which is very important."
Kaymer also had to work hard to win, fending off Englishman Justin Rose at the 20th hole in the day's only match that went extra holes.
"It would have been tough if I lost," said Kaymer. "I was playing very good golf but he came back really strong on the back nine and made a lot of putts. It was a good fight."
Perhaps the biggest upset was Rory McIlroy's defeat, not so much because the No. 7 lost, as the way he was unceremoniously humbled by American Ben Crane, 8 and 7.
Els lost to J.B. Holmes when his putt at the last horseshoed out, while Dane Thomas Bjorn also bowed out, a day after eliminating Woods.
The lower seed won eight of 16 matches. Eight Americans advanced to the final 16, along with five Europeans, two Australians and one South Korean.
Results on Thursday from the second round of the $8.5 million World Golf Championships Match-Play Championship (x denotes seed):
Bobby Jones bracket
Nick Watney (USA x8) bt Lee Westwood (ENG x1) 1-up
Ryan Moore (USA x12) bt K.J. Choi (KOR x13) 5 and 4
Matteo Manassero (ITA x15) bt Charl Schwartzel (RSA x7) 1-up
Luke Donald (ENG x3) bt Edoardo Molinari (ITA x6) 2 and 1
Ben Hogan bracket
Rickie Fowler (USA x8) bt Phil Mickelson (USA x1) 6 and 5
Matt Kuchar (USA x4) bt Bo Van Pelt (USA x12) 3 and 2
Graeme McDowell (NIR x2) bt Ross Fisher (ENG x10) 4 and 2
Yang Yong-Eun (KOR x11) bt Stewart Cink (USA x14) 4 and 3
Gary Player bracket
Martin Kaymer (GER x1) bt Justin Rose (ENG x9) 20 holes
Hunter Mahan (USA x5) bt Robert Karlsson (SWE x4) 2-up
Ben Crane (USA x10) bt Rory McIlroy (NIR x2) 8 and 7
Miguel Angel Jimenez (ESP x6) bt Ryan Palmer (USA x14) 4 and 2
Sam Snead bracket
Geoff Ogilvy (AUS x8) bt Thomas Bjorn (DEN x16) 1-up
Bubba Watson (USA x5) bt Mark Wilson (USA x13) 6 and 5
Jason Day (AUS x10) bt Paul Casey (ENG x2) 4 and 2
J.B. Holmes (USA x6) bt Ernie Els (RSA x3) 1-up