Vijay Singh [Images] and defending champion Tiger Woods [Images] suffered second round defeats at the WGC-Accenture Match Play Championship on Friday, leaving the $7.5 million event without its two biggest draws.

Having never progressed beyond the second round here in five previous attempts, world number one Singh's 3&2 loss to American Jay Haas was not a total surprise.

But Australian Nick O'Hern's 3&1 win over Woods will rank among the biggest upsets, the Australian ending the world number two's 13-match unbeaten streak at the La Costa Resort and Spa and his bid for an unprecedented third consecutive title.

"Nick made all the putts he had to make today and I didn't," said Woods. "He's a very solid player, he doesn't make many mistakes."

Only once before in five previous visits here had Woods failed to reach at least the quarter-finals, falling to Australian Peter O'Malley in the opening round in 2002.

But following that defeat the Woods embarked on a spectacular run, claiming back-to-back titles in 2003 and 2004.

O'Hern said: "It was a good match for me and Tiger was just unfortunate with some putts. I just had to play my own game."

The 32nd ranked O'Hern always represented a potentially tricky test for eight-time major winner.

The Australian lefty had only once before qualified for the elite 64-player field but has excelled in the match play format.

Haas was also no gimme for Singh, the 51-year-old American and U.S. Ryder Cup veteran possessing a solid match play record, including a quarter-final appearance in 2003.

Already battered by days of record rain the tournament will now have to get by without its two biggest names.

With the departure of Singh and Woods third seed Phil Mickelson becomes the tournament's highest ranked player and the man to beat.

Riding the momentum from back-to-back wins at the Phoenix Open and Pebble Beach Pro Am, Mickelson continued his red-hot play disposing of Argentine Angel Cabrera 4&3.

Davis Love III, runner-up to Woods last year and a semi-finalist in 2000, underlined his match play credentials crushing Britain's Lee Westwood 7&6.

"Davis played great he deserved to win," said Westwood. "The course suits him down to the ground, if he keeps playing like that there is no reason he shouldn't go all the way."