Tiger Woods struggled with his short game but dug deep into his reserves to keep in touch with Ernie Els and Michael Campbell, who shared the lead after the second round of the £800,000 Johnnie Walker Classic.

South African Els shot a day's best 67 and New Zealander Campbell a 71, putting them both seven under par at the Ta Shee Golf and Country Club. Woods, who carded a 68 on Thursday, bogeyed three holes but still finished with a level-par 72 for an overall four under, three strokes behind the leaders.

"I held it together but was struggling with the putter and did well to fight back to even for the day," said Woods.

"Tiger is the best golfer in the world by far. He had a pretty mediocre day," said Els, one of only four players to break 70 in the windy conditions.

"If I can score under 70 for the next couple of days then they'll have to come out and catch me," added the South African. Els and Campbell were followed by Nick O'Hern of Australia and Sweden's Marten Olander, who were both at six under after the second day.

Australian Peter Senior and Sweden's Johan Skold are at five under par while Welshman Phillip Price was the best-placed British player on four under after matching Woods' 68-72 start.

Campbell, who has frequently racked up low scores only to finish poorly, said he was not intimidated by the big guns.

"I love to see my name on the leaderboard with the best players in the world." said the New Zealander.