Arizona - Tiger Woods, Steve Stricker and holder Ian Poulter made early exits as the opening round of the WGC-Accenture Match Play Championship lived up to its reputation of wild unpredictability on Wednesday.
There were 14 upsets in all from the 32 matches at Dove Mountain's Ritz-Carlton Golf Club, fulfilling world number one Lee Westwood's pre-tournament description of the first day as "one of the most exciting days of the year".
Three-times champion Woods, striving to end a winless run of 15 months, was eliminated by 65th-ranked Dane Thomas Bjorn after 19 holes.
"I blew it," the 14-times major winner said greenside after going out in the first round for a second time at this event.
American world number eight Stricker, who claimed the 2001 Match Play title in Australia, was stunned by 17-year-old Italian Matteo Manassero 2&1.
Poulter, who beat fellow Englishman Paul Casey 4&2 in last year's final to claim his first PGA Tour victory, was beaten by American Stewart Cink after 19 holes.
A tournament record eight matches went into extra holes but three of the top four seeds ensured a measure of normalcy with comfortable victories on a day of dazzling sunshine, cool temperatures and gusting winds in the Arizona desert.
Top-seeded Briton Westwood never trailed in his match before beating 2007 champion Henrik Stenson of Sweden 3&2.
Second-ranked German Martin Kaymer completed a 7&6 demolition of South Korean Noh Seung-yul and fourth seed Phil Mickelson breezed past Australian Brendan Jones 6&5.
Woods appeared to hold the momentum in his match with Bjorn after sinking an eight-foot birdie putt at the par-four 18th to force extra holes.
However, he pushed his next drive way right into desert scrub from where he needed two shots to get back out onto the fairway. He struck his fourth to 18 feet and missed the bogey putt before conceding the match to Bjorn.
"I had a chance," Woods said after clawing his way back from two down after five holes to go one up after 12. "I had all the momentum going down 18 and just gave it away.
"The ball I should have put in play on 19 and consequently I'm out of here."
Bjorn was gracious in victory.
"The game of golf needs him back at his best," the Dane said. "It was one of those days on the golf course where we're not proud of the way we played, but I'm proud of the way I hung in there."
Poulter's title defence was short-lived. Despite going two up on Cink after 14 holes, he watched his opponent sink several key putts before losing on the 19th green.
"He putted me off the golf course today," the flamboyant Englishman said after becoming the first defending champion in nine years to go out in the opening round.
"That's what you have to do in this format. I did it last year and managed to go all the way. This year I missed my chances and therefore I have been punished."
Stricker had been one up on Manassero after nine holes but made a premature exit from the tournament when the teenager rolled in a 21-foot birdie putt at the 17th.
"It's a big achievement for me," said the Italian, the youngest player ever to compete in the Match Play event.
"I played really well. I achieved a victory against one of the best players in the world and a past champion."
In other matches, US Open champion Graeme McDowell of Northern Ireland hammered American Heath Slocum 4&3, Irishman Rory McIlroy swept aside American Jonathan Byrd 4&2 and Briton Justin Rose won a tight battle with American Zach Johnson 2&1.
South African Ernie Els came from three down after three holes to beat American Jeff Overton on the 19th green and Ryan Palmer reached the second round with a surprise two-up win against fellow American Jim Furyk.Results from the first round of the $8.5 million World Golf Championships Match-Play Championship (x denotes seed):
Bobby Jones bracket
Lee Westwood (ENG x1) bt Henrik Stenson (SWE x16) 3 and 2
Nick Watney (USA x8) bt Anthony Kim (USA x9) 5 and 4
K.J. Choi (KOR x13) bt Retief Goosen (RSA x4) 1-up
Ryan Moore (USA x12) bt Francesco Molinari (ITA x5) 3 and 1
Matteo Manassero (ITA x15) bt Steve Stricker (USA x2) 2 and 1
Charl Schwartzel (RSA x7) bt Ryo Ishikawa (JPN x10) 20 holes
Luke Donald (ENG x3) bt Charley Hoffman (USA x14) 6 and 5
Edoardo Molinari (ITA x6) bt Martin Laird (SCO x11) 3 and 2
Ben Hogan bracket
Phil Mickelson (USA x1) bt Brendan Jones (AUS x16) 6 and 5
Rickie Fowler (USA x8) bt Peter Hanson (SWE x9) 1-up
Matt Kuchar (USA x4) bt Anders Hansen (DEN x13) 22 holes
Bo Van Pelt (USA x12) bt Louis Oosthuizen (RSA x5) 2-up
Graeme McDowell (NIR x2) bt Heath Slocum (USA x15) 4 and 3
Ross Fisher (ENG x10) bt Robert Allenby (AUS x7) 4 and 3
Stewart Cink (USA x14) bt Ian Poulter (ENG x3) 19 holes
Yang Yong-Eun (KOR x11) bt Alvaro Quiros (ESP x6) 20 holes
Gary Player bracket
Martin Kaymer (GER x1) bt Seung-yul Noh (KOR x16) 7 and 6
Justin Rose (ENG x9) bt Zach Johnson (USA x8) 2 and 1
Robert Karlsson (SWE x4) bt Hiroyuki Fujita (JPN x13) 5 and 3
Hunter Mahan (USA x5) bt Sean O'Hair (USA x12) 4 and 3
Rory McIlroy (NIR x2) bt Jonathan Byrd (USA x15) 4 and 2
Ben Crane (USA x10) bt Adam Scott (AUS x7) 4 and 2
Ryan Palmer (USA x14) bt Jim Furyk (USA x3) 2-up
Miguel Angel Jimenez (ESP x6) bt Yuta Ikeda (JPN x11) 2 and 1
Sam Snead bracket
Thomas Bjorn (DEN x16) bt Tiger Woods (USA x1) 19 holes
Geoff Ogilvy (AUS x8) bt Padraig Harrington (IRL x9) 4 and 3
Mark Wilson (USA x13) bt Dustin Johnson (USA x4) 19 holes
Bubba Watson (USA x5) bt Bill Haas (USA x12) 3 and 2
Paul Casey (ENG x2) bt Richard Green (AUS x15) 19 holes
Jason Day (AUS x10) bt Kyung-Tae Kim (KOR x7) 3 and 2
Ernie Els (RSA x3) bt Jeff Overton (USA x14) 19 holes
J.B. Holmes (USA) bt Camilo Villegas (COL x11) 4 and 2