AUGUSTA, Georgia, April 12 (Reuters) - South African Trevor Immelman held steady through the front nine and surged ahead with an impeccable homeward half on Saturday to seize a two-shot lead with one round to play at the U.S. Masters.
Immelman, the overnight leader at eight under par, posted a three-under-par 69 at rain-softened Augusta National for an 11-under 205 total.
The 28-year-old South African stood 18 holes from his first major tournament title, though 13-times major winner Tiger Woods was lurking in fifth place, six shots back.
In second place on 207 was American Brandt Snedeker, who overcame three successive bogeys from the 11th with birdies at 14, 15 and 18. American Steve Flesch shot 69 for 208, one better than Briton Paul Casey, who also registered a three-under 69.
Four-times champion Woods posted 68 for five-under 211.
Immelman, 28, pulled ahead of the pack with birdies at the par-five 13th and par-four 14th and then escaped danger at 15.
The South African's third shot to the par-five hole spun off the green and appeared to be headed down the front bank and into the pond before somehow stopping on the steep slope.Immelman chipped back up to the green and holed a four-foot putt to save par.
He capped off his impressive round with a breathtaking approach to three feet at the last and rolled in his third birdie of the back nine.
World number one Woods, striking the ball beautifully but unable to take full advantage of opportunities, was frustrated with his performance but happy for a chance at a 14th major.
"Today was probably the highest score I could have probably shot," said Woods, who started his round shortly after play resumed following a 40-minute suspension for heavy rain and the threat of lightning in the area.
"I hit the ball well all day, hit a lot of good putts that didn't quite have the right speed or the right line. It was just a touch off," he said, "but, hey, I put myself right back in the tournament."
