WHITE SULPHUR SPRINGS, West Virginia, July 5, 2012 (AFP) - Three-time major champion Singh, who has not won since the 2008 Deutsche Bank Championship, birdied his final four holes to stand atop the leaderboard, one stroke ahead of Americans Jeff Maggert, Jonathan Byrd and Martin Flores.
Singh, who turns 50 next February, shocked even himself with his round.
"I don't know where that came from," Singh said. "I have been playing pretty good golf for a while but just never got any scoring going."
South Africa's Garth Mulroy, Argentina's Andres Romero and Americans Webb Simpson and J.B. Holmes shared fifth on 65 after the opening round of the $6.1 million event.
A week after becoming the first player to win three tour events this season, Woods stumbled to a 71 to stand eight strokes off the pace, complaining that he could not find his touch on the greens.
"I was a little bit off my game," Woods said. "I missed every single putt high. I never hit one. I missed on the high side. I was giving too much break."
Woods, who began on the back nine, birdied the par-4 11th and par-5 12th but took a bogey at 13, missing a five-foot par putt, and a double bogey at the par-5 17th, sending his tee shot into water to the right and botching a two-foot bogey putt. The 14-time major champion made 31 putts on the day.
"I didn't have the speed of these greens at all," Woods said. "My last three tournaments, the greens were awfully quick and they have a lot of swing at the end because of how fast they are."
Woods was 16-for-16 on putts inside 10 feet last week in winning the National. He won the Arnold Palmer Invitational in March and the Memorial last month but has struggled in the majors this season.
Woods hopes to fine-tune his game this week ahead of the British Open in two weeks at Royal Lytham.
Singh opened with a birdie, took a bogey three holes later and birdied the par-4 seventh to make the turn one-under, then caught fire with birdies at 11 and 12 and four more to finish his round, including the par-3 15th and 18th, and the 17th that unwound Woods.
Singh sank a 36-foot birdie putt at the 15th and closed the round by connecting from six feet on the unusual par-3 18th, the last of his 25 putts.
"The greens are receptive to good shots, so if you hit good shots to the pin, they're going to stop," Singh said.
Singh had fired an 81 in the final round at the National last Sunday.
"It's my first good round of the year," Singh said. "It's a good way to start a tournament. I'm looking forward to the rest of the week."
Leading scores on Thursday after the first round of the $6.1 million US PGA Greenbrier Classic (USA unless noted, par 70):
63 - Vijay Singh (FIJ)
64 - Jeff Maggert, Jonathan Byrd, Martin Flores
65 - J.B. Holmes, Webb Simpson, Andres Romero (ARG), Garth Mulroy (RSA)
66 - Ken Duke, Billy Horschel, Jerry Kelly, Sean O'Hair, Scott Piercy, K.J. Choi (KOR), Charley Hoffman
67 - Blake Adams, Colt Knost, Charlie Wi (KOR), Graham DeLaet (CAN), Scott Brown, Richard Lee, Kevin Streelman, Scott Stallings, Patrick Cantlay, Justin Thomas