(CNN) -- World number one Tiger Woods crashed out of the WGC Accenture Match Play Championship in Arizona on Thursday, going down in the second round to South African Tim Clark.
Clark celebrates another birdie on his way to seeing off world number one Tiger Woods in Arizona.
Clark moved into the last 16 4&2, bringing a premature end to Woods' return from an eight-month absence.
The American had not played competitively since his U.S. Open triumph in June, after which he had major reconstructive surgery on his left knee.
"I just happened to catch Tim playing really well and I didn't make enough birdies to answer him," the 33-year-old American told Reuters.com.
"I hit it really good today, I just didn't make enough birdies. Tim made a lot of birdies out there and I didn't answer in the middle part of the round. Consequently I got behind."
Clarke told Reuters.com that he always believed he was in with chance.
"I felt pretty relaxed out there. Luckily I've had the experience of playing with him and I knew I had to treat it like another round of golf and go out and play. It was a great match for me."
In other matches, Englishman Oliver Wilson claimed another big-name victim when he knocked out world number 11 Anthony Kim.
There was further success for England when Paul Casey reached the third round with a 6&4 win over Australia's Mathew Goggin and Ross Fisher ended the run of Pat Perez, the American who knocked out Padraig Harrington in the first round.
However, another Englishman, Lee Westwood, was beaten by Stewart Cink. Meanwhile, world number three Phil Mickelson held off the challenge of Ryder Cup colleague Zach Johnson and will now face Cink in the last 16.