Tiger Woods extends his lead at Chevron World Challenge

But it's not a recent one, either.

Woods' play this week might have been met with a collective shrug two years ago. But in the aftermath of his personal scandal, his delayed return to competitive golf and his winless season, the two-day performance of the world's former No. 1 golfer was notable.

Woods shot a six-under-par 66 Friday after opening the tournament with a 65, and at 13-under 131 he held a four-shot lead over U.S. Open champion Graeme McDowell.

Rory McIlroy and Luke Donald, who stormed into contention with a 66 of his own, were five shots behind Woods, who is a four-time winner of this tournament that benefits his charity, the Tiger Woods Foundation.

"I'm feeling very happy with the progress I've made," Woods said, although he acknowledged that "I didn't hit the ball quite as sharp as I did yesterday."

Woods got it going with an eagle three on the par-five, 531-yard second hole after he reached the green in two shots and sank a 15-foot putt.

The 7,027-yard Sherwood layout in Thousand Oaks features five par-five holes, and Woods is 10 under on the par fives through the first two rounds.

"They're all really reachable" in two shots and "I just felt that's so important to play those holes well," Woods said.

But despite not having a bogey, "I just kept hitting the ball in the wrong spots, kept giving myself these big breaking putts" on Sherwood's slick greens, he said. "The majority of the day I was putting pretty defensively."

Donald appeared headed to an even better finish. After reeling off five consecutive birdies on holes 10 through 14, he was 10 under for the tournament. But he suffered a double bogey on the par-three 17th.

McIlroy had his own double-bogey six on the par-four 18th hole, giving him a 70, and McDowell bogeyed the finishing hole to cap an up-and-down day that ended with a three-under 69.

"I wasn't quite sure where [the ball] was going to go," McDowell said. "To shoot three under and not play my best, I'm pretty happy with that."

Paul Casey, meanwhile, had a hole in one with a seven-iron on the 186-yard 12th hole. The ace helped him shoot 65, the best round of the day, and move to six under for the tournament.

Conversely, Steve Stricker finished four over for the day and the tournament, and he had to rally to achieve that score, which left him in last place. He ballooned to a seven-over 43 on the front nine, which included a triple-bogey eight on the second hole.