J. Pat Carter, Associated Press
Vijay Singh hits from the fourth tee during Friday's second round of the Arnold Palmer Invitational.

ORLANDO, Fla. — Vijay Singh was forced to take four days off from practicing, which was unprecedented. He found himself atop the leaderboard one week later at the Arnold Palmer Invitational, which is not surprising in the least.

Weakened by a stomach virus that caused him to lose 18 pounds in five days, Singh recovered in time to make a strong defense of his Bay Hill title by chipping in twice Friday on his way to a 5-under 65 and a two-shot lead over Carl Pettersson.

The 45-year-old Fijian looked like the model of athleticism on a day of gray clouds and occasional rain, not even remotely resembling someone afraid to stray too far from the bathroom for four days. He had a 9-under 131 total.

Tiger Woods also looked sick, but only after watching putts come up short on shoddy greens. Woods, trying to continue a winning streak that stretches all the way back to September, had to settle for nine straight pars to close out a 2-under 68. He was seven shots behind going into the weekend.

LPGA TOUR: At Huixquilucan, Mexico, Lorena Ochoa shot a 4-over 76 — her highest score in nearly a year — in the MasterCard Classic, leaving the top-ranked Mexican star nine strokes behind first-round leader Jill McGill. Coming off an 11-stroke victory two weeks ago in Singapore in her season debut, Ochoa had six bogeys and two birdies on the hilly Bosque Real Country Club course. The 76 was her highest score since a 77 in the final round of the Ginn Open last April. McGill, the 1993 U.S. Women's Amateur champion who is winless in 13 seasons on the LPGA Tour, eagled the 541-yard ninth hole — her last hole — for a 5-under 67. She also had five birdies and two bogeys.

CHAMPIONS TOUR: At Santa Clarita, Calif., Nick Price birdied the final hole for a 6-under 66 and a one-stroke lead over defending champion Tom Purtzer after the first round of the Champions Tour's AT&T Champions Classic. Price, winless in 17 career starts since joining the 50-and-over tour last year, topped a leaderboard for the first time 54 Champions Tour rounds. He won 18 times on the PGA Tour, including three major victories.

Dana Quigley opened with a 68, Roberts and Graham Marsh shot 69s, and Fred Funk, Jerry Pate, Jeff Sluman, Vicente Fernandez, Andy Bean, Brad Bryant, Dave Stockton and Joe Ozaki had 70s. Gil Morgan, the 1996, 1997 and 2004 winner, shot a 73.