Vijay Singh fired a 7-under 63 on Thursday to take a 1-stroke lead after the first round of the Greenbrier Classic.

Singh, a three-time major champion, ended his round at the Old White TPC course at The Greenbrier with four consecutive birdies. That gave him the clubhouse lead, and nobody beat his number.

"Gosh, I don't know where that came from," Singh said. "I've been playing pretty good golf for a while but just never got any scoring going. But today seemed I hit it close and drove the ball really well, hit a lot of greens and made some nice putts."

Singh, 49, is a Hall of Famer golfer but hasn't won a major tour event since 2008. This season, he finished in the top 10 at the Byron Nelson Championship in May, but otherwise has had an unremarkable year.

He called Thursday his "first good round of the year," and it's put him at the front of the field.

Tiger Woods, fresh off his win at the AT&T National, shot a 1-over 71, as did Phil Mickelson.

Woods began on the back nine and birdied two of his first three holes. However, he started having problems after that, with a bogey at 13 and a double bogey at No. 17.

He birdied the first hole to get back to even par, but followed it up with a bogey. Woods carded one more birdie and bogey to finish off the scoring in his inconsistent round.

"I just didn't quite have my game or didn't have the speed on the greens, too," said Woods. "It was quite a big adjustment from playing my last three events for the green speeds, so I struggled with it a little bit."

Because of those struggles, Woods finds himself tied for 88th, and he'll have to make up a lot of ground because so many players took advantage of the course's scoring conditions.

Jeff Maggert, Martin Flores and Jonathan Byrd share second place after firing 6-under 64s.

U.S. Open champion Webb Simpson carded a 65 and is tied for fifth with J.B. Holmes, Andres Romero and Garth Mulroy.

Singh got his round started with a birdie at the par-4 first, where he knocked his approach within three feet and kicked in the putt. He bogeyed the fourth after finding a fairway bunker, but got the stoke back with another strong approach at the par-4 seventh. Singh's tee shot had landed in the rough to the left of the fairway, but his second shot stopped five feet shy of the pin.

But he really got going on the back nine. Consecutive birdies from the 11th pushed him to 3-under, and he started a run of outstanding golf at the par-3 15th.

After missing a six-footer for birdie at the 14th, Singh managed to hole a 36- foot birdie chance at the next.

"I said, 'Well, it made up for the last one,'" Singh said.

He sank birdie putts of four, three and seven feet at the final three holes. Singh's birdie at the 17th came after he drove into a greenside bunker, but the other two were set up by solid shots.

"The greens are receptive to good shots, so if you hit good shots to the pin, they're going to stop," Singh said.

Byrd began on the 10th tee and had reached minus-6 before stumbling to a bogey at the eighth. However, he birdied his last to match the others one stroke behind Singh.

Maggert and Flores also both started on the back nine and drained six birdies during clean rounds.

"For the most part I was in real good control," Flores said. "You know, you have a few loose shots here and there, but that's why you have a good short game. I've been working really hard on that."

Behind the fifth-place group are seven players tied for ninth at 4-under 66 -- Ken Duke, Billy Horschel, Jerry Kelly, Sean O'Hair, K.J. Choi, Scott Piercy and Charley Hoffman.

NOTES: Defending champion Scott Stallings shot a 3-under 67 and is tied for 16th...Amateur Justin Thomas is also part of the 16th-place group...Tom Watson, The Greenbrier's golf professional emeritus, shot even-par 70.