Tiger Woods' closest challengers were left scratching their heads in disbelief after the world No 1 took control of the Northwestern Mutual World Challenge with a 10-under-par 62.

Five-time champion Woods played near-flawless golf on Friday in the second round of the tournament he hosts, equaling the course record he set at Sherwood Country Club in 2007 to end the day two shots ahead of the rest of the field.

His stunning 10-birdie 62 was five strokes better than the next-best score in an elite field of 18, Northern Ireland's defending champion Graeme McDowell and England's Ian Poulter both having carded 67s.

"Amazing what Tiger did out there," American Matt Kuchar said after shooting a second successive 68 to sit three strokes off the pace in third spot at eight under.

"It's just some incredible golf. The rest of us, my four-under score is kind of a good barometer. That's some good quality playing. Ten under is an amazing round of golf, but I'd certainly take two more rounds of four-under par."

Kuchar expressed sympathy for two-time World Challenge champion McDowell, who was paired with Woods for the second round but lost ground despite firing a five-birdie 67.

"I kind of felt sorry for Graeme," said Kuchar, a double winner on the 2013 PGA Tour.

"I saw he posted a five-under-par round, and it must have felt like it was two or three over.

"It's tough when you are paired with a guy like that. It makes you feel like you are not doing much. But the rest of us just go about our business."

McDowell, who clinched the World Challenge for the first time with a playoff victory over Woods in 2010, was full of admiration after having a ringside seat on Friday for the American's 62.

"It was a clinic," the Northern Irishman said. "It was cool to see that kind of golf. He was under control. He hit it down the middle of every fairway."

First-round leader Zach Johnson birdied his final hole for a bogey-free 68 to secure outright second place and was largely satisfied with his round.

"I had opportunities," said Johnson, who had opened with a 67.

"I had some putts on the back nine, opportunities where I could have got up and down for birdie and a couple of those par-fives that I didn't.

"Other than that, it was a pretty solid day. No complaints. I mean, you finish with a birdie on 18, you take it."

The average score on Friday was 70.78, almost nine strokes worse than the 62 posted by Woods, who is seeking a record sixth victory at the event and his sixth tournament win this year.

(China Daily 12/08/2013 page11)