American Chad Campbell won the Bay Hill Invitational by six shots on Sunday over Australian Stuart Appleby after a bogey-free six-under-par 66 delivered his second PGA Tour career victory.

Campbell, who said he was inspired by Arnold Palmer, came from four shots behind to overhaul Appleby, who began the day in front but never got going and lost the lead on the 11th hole before drifting as the American finished on 18-under 270.

Campbell had said it would take an Arnold Palmer-like charge to beat Appleby and was encouraged after playing with the all-time great in the first two rounds. "We owe so much to him," said Campbell. "It was really an inspiration."

Scott Verplank and Australian Adam Scott tied for third on 277, while Jerry Kelly, who had fought a stomach ailment all week, finished alone in fifth another stroke back.

Rookie Zach Johnson, Trinidad and Tobago's Stephen Ames, Britain's Darren Clarke and Japan's Shigeki Maruyama finished on 280 and tied for sixth.

WOODS' WOES

The woes of world number one Tiger Woods continued as he was placed in a tie for 46th on even-par 288, 18 shots behind Campbell.

It was Woods' sixth-poorest finish as a professional and his worst performance since the 1999 Bay Hill Invitational when he tied for 56th.

Campbell, 29, was nearly flawless on a day when the leaderboard saw many changes but never in the top two spots as Campbell and Appleby duelled with each other over the 18 holes.

Campbell had the best of the battle early on, making three birdies in the first nine holes and trimming Appleby's four-shot lead to one at the turn as the Australian bogeyed the ninth.

"I was hitting right at the pin," Campbell said. "A couple of them were pushed or pulled that way, but I felt really comfortable with my game. I felt like I was hitting it good enough to be going at those pins."

Campbell caught Appleby on the 11th as he made bogey when he missed the green and could not convert a 14-footer for par.

The American took the lead for good on the 14th hole when the Australian bogeyed yet again, three-putting the par-three from 43 feet.

Campbell went on to birdie two of the last four holes to finish on 18-under, while Appleby completed the last four holes at 3-over-par.

BIGGEST COMEBACK

Campbell made up 10 shots over the last 12 holes, going from four shots back to six ahead for the biggest comeback at the Bay Hill Invitational since Gary Koch came from six shots back in 1984 to win in a playoff.

"I really screwed up the back nine," Appleby said. I felt all right all day but Chad just kept making every putt.

"I was trying to just ignore that and continue and do what I needed to do and hit my shots. But today he played great. He just outplayed me, no two ways about it."

Campbell had certainly found inspiration from four-times Masters champion Palmer.

"Playing with him (Palmer) the first two days that was awesome," Campbell said. "It was such a good experience for me and not knowing how many more tournaments he's going to play in, just getting the experience to play with him (was great).

Campbell, whose Bay Hill Invitational crown joins his Tour Championship title from last year, has bigger wins on his mind.

"I was really working hard and looking forward to the Masters and also these tournaments, as well," he said. "But I'm trying to get everything (together) for the Masters so I will be a lot more prepared than I was last year."