Brett Wetterich stands alone in second place after a 6-under-par 66. Jesper Parnevik was one stroke further back at minus-5. Nick Watney, Woody Austin and Aaron Baddeley share fourth place at 4-under-par 68.
The 2004 Bay Hill Invitational winner tripped to another bogey at the par-4 16th. However, Campbell holed a 70-yard shot for eagle at the par-5 17th to jump to 2 under.
On the front side, Campbell caught fire. He rolled in a 6-foot birdie putt at the first and made it two straight as his birdie putt at two found the bottom of the cup.
The 30-year-old moved to 5 under with a 10-foot birdie putt at the fourth. Campbell kept moving with a birdie on No. 6 after he dropped his 9-iron within 6 feet.
The Texan climbed to 7 under when his 25-foot birdie putt at the eighth fell into the cup. Campbell closed his round with a birdie at the ninth from 15 feet out.
'It was obviously a good day. It was a tough day out there though,' said Campbell, whose round started with temperatures in the low 50s. 'The wind was blowing, it was cold this morning, and you know I was just able to get through the first few holes when it was really, really tough. Then it let up a little bit. I definitely made my share of putts today.'
Wetterich got off to a quick start with a birdie at the first from 6 feet out. He came right back with a birdie on the third. The 31-year-old moved to 3 under when he got up and down from a greenside bunker for birdie at the par-5 sixth.
The two-time winner on the Nationwide Tour birdied the ninth from 5 feet and 10th from 12 feet around the turn to move to minus-5.
'I hit a lot of greens and a lot of fairways,' Wetterich said. 'I was hitting a lot of shots close today and making a few putts.'
Wetterich, who lives 10 minutes from the course, parred seven straight holes before kicking in a 3-foot birdie putt at the last to get within two shots of Campbell.
'I'm comfortable. I live ten minutes from here,' said Wetterich. 'I'm staying at home and I've got a bunch of family with me and it's nice to come out and shoot a good round for them.'
Justin Rose and defending champion Todd Hamilton lead a group of 14 players at 3-under-par 69. Among those at minus-3 are Kevin Na, Sean O'Hair, Bob Estes, Brad Faxon and Lee Janzen.
Joey Sindelar, the 1988 champion of this event, heads a group of 20 players at 2-under-par 70.