(CNN) -- Phil Mickelson charged past arch-rival Tiger Woods on the back nine of the third round on Saturday to take a two-shot lead at the HSBC Champions tournament in Shanghai.
World number one Woods led by two shots after a birdie on the 10th at the Sheshan International and looked set to pull clear of his chasers at the $7 million World Golf Championship (WGC) event, but he could not match the brilliance of Mickelson in the closing holes.
Mickelson conjured up birdies on the 14th, 15th and 18th for a five-under 67 and a three-round 14-under total of 202.
Woods bogeyed the 11th and could only par home for a 70 and was joined on 12-under by fellow American and his joint overnight leader Nick Watney, who eagled the par-five 18th to re-ignite his challenge.
A fourth American, the unheralded Ryan Moore, birdied the last for a 70 and is a shot further back on 11-under.
The European challenge is led by Lee Westwood, who charged through the field with a joint best of day seven-under 65 for 10-under 206, posting his score before a tricky wind made the back nine a tougher test for the later starters.
Woods told Sky Sports that the weather, with rain and a stiffer breeze forecasted, could be a factor on the final day as he locks horns with world number two Mickelson in the last group with Watney.
Woods has won 17 of the 30 WGC events he has contested but was disappointed by his play in the third round.
"I didn't make any birdies, I didn't play the par fives particularly well and consequently I'm two back," he said.
Mickelson, who missed several tournaments earlier this year as both his wife and mother battle breast cancer, has been in fine form at the end of the season and beat Woods to the Tour Championship on the PGA Tour and on the evidence of Saturday's play could be due a repeat.
Superb approach shots to the par-five 14th and testing par-four 15th set up easy birdie putts and his lead would have been greater but for narrowly missing cast-iron chances on 16 and 17.
After a superb drive, his approach to the par-five 18th came up short, but he showed his impeccable touch around the green to put his third stone dead for his sixth birdie of the round, with just one dropped shot.
Woods hit an errant tee shot on the 18th and after laying up found a greenside bunker with his third, scrambling par in typical style to avoid going three shots behind going into the final round.
He has yet to win the HSBC Champions after two runner-up finishes, while Mickelson claimed victory in Shanghai in 2007 in a rare foray overseas and found strong support among a sizable gallery as golf continues to increase its popularity in China.
He is relishing the prospect of renewing his rivalry with Woods in the last major strokeplay tournament of 2009.
"I love the fact I've got a two-shot lead and I love the fact we get to play together.
"There's a number of guys who are going to be in mix aside from Tiger and myself, but it's fun we have a chance to play together," he told the official European Tour Web site.