Defending champion Bo Van Pelt came achingly close to a miraculous 59 on Saturday as he shared the CIMB Classic lead with Robert Garrigus, while Tiger Woods' charge fell apart on the back nine.

In a superb day of action at the co-sanctioned US PGA and Asian Tour event Van Pelt, continuing the form that took him to victory in Perth last weekend, needed to birdie the last hole to claim a rare sub-60 round but he double-bogeyed to close on 62.

Van Pelt's three-day total of 16-under 197 put him level with overnight leader Garrigus heading into the final day, with Chris Kirk one shot back and Brendon de Jonge and Jbe Kruger two adrift on a tight leaderboard.

Greg Chalmers (69) was the best Australian but he fell from equal third place to a tie for seventh, four shots off the pace.

Woods had started promisingly with five birdies up to the turn but the wheels then came off with three bogeys and a double bogey, and he wound up with a 69 for 11-under 202 and a share of 10th.

Van Pelt, defending a title for the first time, insisted he had no regrets about his last hole, where he overcooked his tee-shot, miscued into a greenside bunker, then three-putted.

"I wouldn't do anything different," he said.

"Obviously it's disappointing to finish with a double (bogey), but I look back on the 17-and-a-half holes I played, and hopefully that will carry over into tomorrow, not the last half."

Woods was left to rue a wretched close at a steamy Mines Resort and Golf Club as he found water on the par-three 14th for double-bogey and dropped strokes on 12, 16 and 17, making the 14-time Major champion a long-shot for victory.

"I need to go out and shoot something really low like what Bo did today or something like that. That might not even do it," Woods said.

As marshalls struggled to control heaving galleries surrounding Woods, the 74-time PGA Tour winner got off like a shot with a 10-foot birdie on one and a six-footer on three to move to 11-under, two shots off the lead.

Further up the course, world No.6 Jason Dufner suggested it was about to be a low-scoring day with a hole-in-one on the 201-yard, par-three seventh, his first in a competitive round.

Round-two leader Garrigus started poorly with two bogeys, enabling Woods to catch him at the top of the board with his third birdie of the day on the par-four fifth.

As Woods rolled in birdies on six and eight, Van Pelt roared through the front nine to turn in 29, raising expectations he could finish below 60.

Three birdies in a row on 10, 11 and 12 gave last year's winner Van Pelt the outright lead, and he gobbled up a short putt on the par-three 16th to move to 10-under for the day.

Van Pelt was motoring, but Woods' momentum was halted when he sliced his tee-shot into rough on 12 and then bogeyed after missing a short downhill putt.

He recovered with a birdie on 13, found water on the par-three 14th for double-bogey five, and then hit back again with a birdie on 15 - before dropping shots again on 16 and 17.

However, all eyes were on Van Pelt and the American went close with a curling eagle putt on the 17th, before seeing his 59 hopes dashed in front of big crowds at the last green.