Rory McIlroy slumped out of the WGC-Accenture Match Play Championship after being taken to a 19th hole by American Harris English.
The world number seven appeared to have victory in his second-round match at Dove Mountain within his grasp as he hit form on the back nine.
The Northern Irishman won four out of five holes to lead by one after 16 but English, impressive winner over Lee Westwood in round one, replied to take the contest to sudden death.
It was at the first extra hole that McIlroy's touch deserted him as he failed to recover from a poor tee shot.
He went wide to the left and could then only pitch into desert rough between a bush and a tree. From there he overshot the green and there was no way back.
It was a disappointing end to a high-quality contest in which few other holes had been settled by mistakes.
McIlroy might have rued a missed putt at the ninth that would have put him ahead when English struck out by taking the 10th and 11th.
But McIlroy, whose iron play had been outstanding, found his touch on the greens to win the 12th, 14th, 15th and 16th, all with birdies, and edge ahead for the first time.
Justin Rose also saw his bid end at an extra hole, with the reigning US Open champion beaten by veteran Ernie Els on the 20th.
There had been little between the two players throughout. However Rose's undoing came as he failed to get his third shot to the par-five hole out of a bunker while Els chipped superbly from just wide of the same sand to set up a birdie.
Top seed Henrik Stenson also fell by the wayside when he went down 4&3 to Louis Oosthuizen of South Africa.
The former Open champion won three of the first four holes against a sub-par Stenson and maintained control before ending the match with a birdie at the par-four 15th.
McIlroy's fellow Ulsterman Graeme McDowell had better fortune though as he produced a stirring comeback for a second day in succession to beat Hideki Matsuyama on the 18th.
McDowell was four down after seven holes of his first round against Gary Woodland and a similar scenario unfolded as Matsuyama won three of their first six.
Yet McDowell had not been playing badly and he was certainly out of luck as Matsuyama chipped in from the rough at the second.
The 2010 US Open winner maintained a steady course and birdies at the eighth and ninth set up a tight back nine.
Matsuyama eventually cracked when he missed a short putt at the 17th to allow McDowell back level and the Japanese player compounded that error by putting his tee shot at the last into a bunker.
McDowell parred the hole to complete another fine fightback.
Sergio Garcia overcame American Bill Haas 3&1 having been two down after seven, but was back to all square after 11. He then won four of the next six holes to take victory on the 17th.
Garcia will next play Rickie Fowler, who won a high-quality match with this season's form player Jimmy Walker one up.
The pair traded holes throughout but Fowler edged ahead by taking the 14th, 16th and 17th.
French Ryder Cup hopeful Victor Dubuisson saw an early three-hole lead wiped out but recovered his poise to beat Peter Hanson 3&1.
American Jordan Spieth, the 2013 PGA Tour rookie of the year, was always in command against Denmark's Thomas Bjorn before wrapping up a comfortable 5&4 victory.
Also in the Gary Player group Matt Kuchar beat Ryan Moore on the 18th.
Bubba Watson, who led by three after just four holes, survived a late wobble before seeing off Jonas Blixt two up.
Blixt threatened to make life difficult by winning the 12th and 14th, but short missed putts at the 15th and 16th and a penalty drop on the last ended his hopes.