Michael Campbell remained at the top of the leaderboard after round two, but was joined by the imposing figure of Ernie Els on seven under par. Els shot a best of the day 67, five under par, despite visiting six greenside bunkers on the tricky Westin Resort Ta Shee layout.
Els, who was beaten in a play-off by Tiger Woods in the event last year, dropped two shots but fired seven birdies in his round.
Campbell added a 71 to his first round 66 to continue the splendid form he has displayed of late. Tournament favourite Tiger Woods had an up and down day and eventually finished with a level par 72 for a four under par halfway total
Chasing his fifth successive tournament win and his 10th of a fantastic 1999, Woods closed the second day on four under, the same score as fellow American Jim Furyk.
Swede Johan Skold, who shared the overnight lead with Campbell and Jeremy Robinson, suffered a disappointing 73 to move to five under while Welshman Phillip Price followed his 68 on Thursday with a 72.
Marten Olander, of Sweden, and Australia's Nick O'Hern go into the third round a shot off the lead, in joint-second, after carding rounds of 70 and 71 respectively.
