Tiger Woods lost 4&2 to Tim Clark to crash out of the WGC Accenture Match Play Championship in the second round.
But the world number one, making his comeback after major knee surgery, refused to be too downcast.
"I hit one bad eight iron and one bad drive so I'm happy with the way I was striking the ball," he said.
"Tim is a wonderful player and he made birdies while I didn't sink enough putts. I feel great, though, and I will go home to evaluate what to do next."
Woods jumped into an early lead with a birdie at the second but Clark hit back to win five and six.
The American restored parity with a birdie on seven, but his South African opponent took command with consecutive birdies on 11, 12 and 13.
Woods holed an outstanding bunker shot on 14 to reduce the gap to two, but his challenge was effectively ended by a wayward tee shot on the driveable par-four 15th.
He blocked his drive out to the right, but it bounced off a cart path into the desert and out-of-bounds.
Woods trudged back to the tee and found the middle of the putting surface with his third shot, but he missed the par putt, leaving Clark with two putts from 20 feet to go three up with three to play.
The South African then hit his tee shot on the par-three 16th to four feet while Woods missed the green to the right.
When his chip stopped 18 inches short of the hole, he removed his cap to signal the end of his comeback.
"I had to try and forget who I was playing," said Clark after his victory.
"I played him here a couple of years ago so I did know what to expect but I was a little nervous on the first tee.
"He may have been a little rusty but he was still going to be able to play some shots that I couldn't.
"He holed a great bunker shot on 14 and it was game on again, but he made a couple of mistakes near the end."
Clark will play Rory McIlroy in round three after the Northern Irishman birdied the last two holes to beat Hunter Mahan one up.
The American opened up a two-shot lead on the 12th, but McIlroy hit back on the 13th and a Mahan error on 14 levelled the match.
McIlroy finished with four threes, sinking 10 and 20 feet putts on 17 and 18 respectively, to wrap up victory.
"I was standing on 13 at two down, but I dug deep and played my best golf when I had to which was satisfying," said the world number 17.
 Wilson claimed a prize scalp in American Anthony Kim |
"It was a great way to finish and it gives me momentum going into the game against Tim."
Lee Westwood was the only casualty on an otherwise great day for England's golfers.
He squared his match with Stewart Cink on 17, but eventually lost on the 23rd when he made his first bogey of the tournament.
Paul Casey and Ross Fisher were the big winners.
Casey, who has a home two hours up the road in Scottsdale, won four of the first nine holes against Australia's Matthew Goggin and sank birdies on 13 and 14 to run out a comfortable 6&4 winner and set up a meeting with Sweden's Peter Hanson, who beat Canada's Stephen Ames 2&1.
Fisher birdied four of the first eight holes to go up four up on America's Pat Perez, then closed out the match with an eagle on the 13th. Fisher takes on Jim Furyk after the American overcame Germany's Martin Kaymer 4&2.
Oliver Wilson was also in impressive form, sinking eight birdies to lead by two at the turn on his way to a 3&2 win over America's world number 11 Anthony Kim. His reward is a third-round match with Justin Leonard who defeated Davis Love III with a par at the last.
Luke Donald recovered from two down with two to play to beat Vijay Singh. A Donald birdie at 17 and Singh bogey at 18 took the game down the 19th and the Fijian left his par putt short to hand victory to the Englishman who will play Ernie Els next.
The South African was never behind as he beat Steve Stricker 3&2.
Ian Poulter capped a remarkable day with a one up victory over Charl Schwartzel. The South African played a bogey-free round, but Poulter sank three birdies, including what turned out to be the crucial one on 17.
Poulter meets Sean O'Hair who defeated his fellow American Boo Weekley 2&1 in a scrappy match. The duo's combined score was nine over par after 11 holes, but O'Hair hit a couple of birdies in the closing holes to secure the win.
Elsewhere, Phil Mickelson survived a late charge from Zach Johnson to win at the last to set up a clash with fellow American Cink.
And Spain's Miguel Angel Jimenez was overwhelmed by Camilo Villegas, who birdied four of the first five holes on his way to a 5&4 win. The Colombian plays Geoff Ogilvy, who beat Shingo Katayama on the 19th.
