A – Adam Scott has suffered an upset loss in the opening round of the WGC Match Play Championship.

Robert Rock added another big scalp to his recent collection when he knocked Scott out of the tournament in Tucson.

Making his debut in the event a month after beating Tiger Woods and the world’s top four in Abu Dhabi, the 34-year-old new English star overcame Australia’s world No.8 on the final green.

John Senden defeated Englishman Simon Dyson, but South African Louis Oosthuizen accounted for Aaron Baddeley.

The highest-ranked American, Steve Stricker at No.5, advanced by beating Kevin Na on the 17th hole.

Tiger Woods lost the first two holes to Gonzalo Fernandez-Castano and had to make an 8-foot par putt on the third hole to avoid an even bigger deficit.

Woods won three of the next six holes, however, including a 50-foot birdie on the seventh, and was one up at the turn.

One putt changed everything for Ryo Ishikawa and sent Riviera winner Bill Haas home in a riveting start to the event.

Ishikawa was on the verge of losing his first-round match on the 17th hole when he hit 7-iron to 18 feet.

Haas was 1 up, and he stuffed his approach to about 5 feet.

But the Japanese star holed his birdie putt, the match went back to all square when Haas missed his putt. Ishikawa then won on the 18th hole with a par.

“Maybe more than myself, Bill felt pressure, especially since I am ranked lower and being the first match of the week,” Ishikawa said.

“The longer the match went, it worked better for me.”

Among the early surprises was Bae Sang-Moon, making his Match Play debut.

He won four holes in a five-hole stretch on the back nine for a 4-and-3 win over Ian Poulter, who won the tournament two years ago.

Five of the opening six matches reached the 18th hole, with two of them going to sudden death, as the format lived up to its reputation as the most exciting in golf.