Former British Open champions Ben Curtis and Ernie Els each shots rounds of 5-under-par 67 and are tied for third place with Jason Gore, Lucas Glover and Bob Hope Chrysler Classic winner Chad Campbell at Bay Hill Golf Club and Lodge.
Woods, who won this title from 2000-2003, began on the back nine Thursday and made the turn at even par. He birdied the first hole, then ran home a 10-foot birdie putt at the third. Woods made it two in a row with a tap-in birdie at four, then reached 4 under par with a birdie at the par-5 sixth.
Things came undone for the top-ranked player in the world. Woods missed a very short par putt at the seventh, then dropped another shot at the eighth. Woods holed a 3-footer for par at the ninth to stay at minus-2.
Wilson started on the back nine Thursday with a 35-foot birdie putt at the 11th. He parred his next three holes, but went on a birdie run that jumped him up the leaderboard.
At the 15th, Wilson hit a 9-iron to 25 feet and converted the birdie putt. He birdied the par-5 16th and capped off his third birdie in a row with a 40-footer at the difficult, par-3 17th.
He parred his first five holes on the second nine, then reached the green with his second shot at the par-5 sixth. Wilson two-putted for birdie from 20 feet and hit an 5-iron to 10 feet to set up his final birdie at the eighth.
Wilson, best known until this year as one of Annika Sorenstam's partners in the first two rounds of the 2003 Colonial, has participated in 10 tournaments so far this season and has started well. He has six rounds in the 60s, including a 64 at the Nissan Open, where he tied for seventh.
'I seem to be putting a lot of rounds together where I hit the ball nice and give myself a lot of chances,' said Wilson. 'That's what I've always been looking for, and so far this year, I've done that a lot, so it's quite pleasing.'
Bryant also played the back nine first at Bay Hill on Thursday and flew out of the gate with a 7-foot birdie putt at the 10th. He added another birdie at the 12th from six feet, then got to 3 under par with a 17-footer at No. 15.
Bryant, who won twice last year, including a wire-to-wire win at the TOUR Championship, hit a 3-iron from 220 yards out for his second at the par-5 16th. His approach landed 12 feet from the hole and he rolled in the eagle putt to get to minus-5.
He dropped his only shot of the round at the 17th when he three-putted, but came back with solid golf on his second nine. At the second, Bryant holed a 30-foot, downhill birdie putt and he collected his final birdie from 10 feet at the fifth.
'It was an exciting round for me, most encouraging round that I played this year, because I finally went out and made some birdies which is something I had not done all year,' said Bryant, who was rehabbing his surgically-repaired knee at the start of the season. 'I felt really good about the round.'
Sergio Garcia, Lee Westwood, Carlos Franco, Robert Allenby and Tom Pernice, Jr. are knotted in eighth place at 4-under-par 68.
Vijay Singh, the second-ranked player in the world, birdied his last hole Thursday for a 1-under-par 71. He is part of a group tied for 39th place.
Kenny Perry won the championship last year, but is not on hand to defend his title. He underwent knee surgery earlier in the week and will miss a little over a month.