Defending champion Vijay Singh holds a two-shot lead after the second round of the Arnold Palmer Invitational in Orlando.
The Fijian carded a round 65 to post a nine-under-par 131 halfway total, two strokes clear of Carl Pettersson and three in front of Lee Westwood.
Ken Duke and Jim Furyk later joined Westwood at six-under, but Tiger Woods is seven shots off the lead and has plenty of work to do if he is not to be frustrated in his quest for a seventh successive title.
Singh, who has just recovered from a bout of food poisoning, opened with a bogey but made four birdies and an eagle at the par-five sixth as he moved clear of the field.
"I hit the ball really good off the tee, gave myself a lot of birdie chances and also helped by chipping in twice as well," said the 45-year-old.
"I'm not doing anything special, not doing too much wrong either, just cruising along."
Singh said he lost nearly 20 pounds last week due to a severe bout of food poisoning he contracted on his way back to Florida after the Johnnie Walker Championship in India.
He was in such a bad state with dehydration that he even went to hospital, where he was hooked up to an intravenous drip.
"I thought I was going to pull out of this tournament but on Friday I started to (feel a little better)," he said.
Westwood managed only three birdies and dropped a shot at the eighth as he could only improve his position by two shots after opening with a round of 66.
Woods began with a disappointing round of 70, but he began to move in the right direction with birdies at the second and sixth holes.
However, after bogeying the eighth hole he managed just one more birdie at the ninth before making par throughout the back nine.