Tiger Woods welcomed back the "good times" as he completed his return from knee surgery by winning the Arnold Palmer Invitational in dramatic fashion at the final hole at Bay Hill on Sunday.

Woods landed the 66th PGA Tour title of his career and his sixth victory at Bay Hill in just his third event since returning from reconstructive knee surgery.

The world number one and defending champion started the day in second place, five shots behind overnight, seven-under-par leader Sean O'Hair, but he clawed back that deficit in 15 holes and took the lead at the 16th.

There was still a twist in the tail as Woods bogeyed the 17th to fall back into a tie at four under par heading to the last.

Both players found the fairway off the 18th tee but while O'Hair sent his second shot to inside 39 feet, his rival put the pressure on by placing his second 16 feet from the hole.

O'Hair sent his putt to three feet, leaving Woods to putt for the title. He had needed a 25-foot birdie to see off Bart Bryant on the same hole 12 months ago, with O'Hair watching him as his chance had gone earlier in the round.

This time O'Hair had to watch again with much more on the line as, in near darkness, Woods drained his putt to take the title and seal another famous victory, nine months on from his last triumph in the US Open at Torrey Pines.

"It feels good to be back," Woods said.

"To feel the heat on the back nine on Sunday like that. To have to make a putt at 14 (to save par) and to make that putt, those are good times.

"It feels good to be back in contention again and to feel the rush and to have to deal with everything coming down the stretch.

"It's been a while, obviously since the US Open that I've had to deal with the back nine on Sunday and it was good."

O'Hair, Woods and Zach Johnson, on one under par, had teed off in an expanded final group of the day following a more than 90-minute rain delay following heavy rain in central Florida.

Having saved par at the par-three 14th after finding a greenside bunker off the tee and putting out from 15 feet, Woods caught O'Hair at the 15th green with a birdie three as his rival parred and the Americans were tied at five under, three shots clear of the field.

Woods missed the fairway at 16 but O'Hair sent his second shot with a hop off the bank and into water on the way to a bogey.

Woods laid up 109 yards from the hole but his third shot was a beauty, a pitching wedge to inside four feet.

He holed his par putt and with two to play was at five under and alone in the lead for the first time since winning the US Open from Rocco Mediate at the 91st hole last June.

Then came the bogey at 17, Woods having to blast out of a greenside bunker, his ball right up against its steep front wall and resting on the bent left knee that had undergone reconstruction last summer.

He showed no ill effects and so it proved as he returned to the winner's circle minutes later with a closing 67 to finish at five under, one shot better than O'Hair, whose 73 still gave him second place, his fourth top-10 finish in eight starts this year.

O'Hair was left to rue his inability to close the deal but preferred to look at the plus points from his defeat.

"I've got to look at the positive side of this," he said.

"I'm playing great, and the swing changes that I'm making are coming around, and obviously I think today just kind of proves that I still don't quite have it yet. But that doesn't mean I'm not going in the right direction.

"I think all in all I take nothing but positives from this.

"Obviously it's just a little bit disappointing that I couldn't close it."

Johnson took third place at two under following a 69 while Australia's John Senden shot a 67 to finish in a tie for fourth at one under alongside Americans Pat Perez, Scott Verplank and Nick Watney.

Their compatriots Kenny Perry and first-round leader Jason Gore tied for eighth at level par with Sweden's Daniel Chopra while Padraig Harrington closed with bogeys at the 16th and 18th to end at one over par in a tie for 11th.

Collated final round scores & totals in the USPGA Tour Arnold Palmer Invitational presented by MasterCard, Bay Hill Club & Lodge, Orlando, Florida, United States of America

(USA unless stated, par 70):

275 Tiger Woods 68 69 71 67

276 Sean O'Hair 67 65 71 73

278 Zach Johnson 72 69 68 69

279 Nick Watney 67 71 73 68, Pat Perez 70 70 70 69, John Senden (Aus) 70 69 73 67, Scott Verplank 70 69 71 69

280 Kenny Perry 70 71 72 67, Daniel Chopra (Swe) 68 71 72 69, Jason Gore 65 70 74 71

281 Kevin Na 69 70 76 66, Ben Crane 70 69 75 67, Robert Allenby (Aus) 71 65 74 71, Lucas Glover 71 71 69 70, Webb Simpson 70 71 70 70, Padraig Harrington (Irl) 70 68 73 70

282 Bob Estes 74 67 71 70, Vaughn Taylor 70 68 74 70, Ryuji Imada (Jpn) 70 66 73 73, Lee Janzen 67 71 73 71, Brandt Snedeker 73 70 67 72

283 Hunter Mahan 67 71 74 71, Chad Campbell 68 74 69 72, George McNeill 70 72 72 69, James Nitties (Aus) 70 71 74 68, Charles Howell III 71 68 74 70

284 Jeev Milkha Singh (Ind) 71 68 74 71, Corey Pavin 72 70 70 72, Mark Wilson 67 71 74 72

285 Justin Rose (Eng) 75 67 73 70, Tim Herron 66 72 74 73, Mathew Goggin (Aus) 70 72 71 72, Stewart Cink 70 71 72 72, Johnson Wagner 69 75 72 69, Cliff Kresge 74 68 71 72

286 Steve Marino 73 68 75 70, Paul Goydos 74 70 74 68, Retief Goosen (Rsa) 74 71 72 69, Steve Lowery 69 71 77 69

287 Graeme McDowell (NIrl) 71 69 73 74, Brian Gay 68 74 72 73, Tom Lehman 72 73 72 70, Heath Slocum 69 75 72 71, J.B. Holmes 73 69 72 73, J J Henry 68 71 79 69, Trevor Immelman (Rsa) 71 73 71 72, Mike Weir (Can) 71 72 72 72

288 Jeff Overton 66 73 75 74, Chris DiMarco 73 70 71 74, David Toms 71 73 71 73, Rocco Mediate 68 76 70 74

289 Jerry Kelly 69 73 76 71, Brad Faxon 70 72 75 72, D.A. Points 73 70 73 73, Marc Turnesa 72 73 74 70, Peter Lonard (Aus) 72 72 77 68, Tommy Armour III 70 74 76 69, Stuart Appleby (Aus) 67 72 80 70

290 Jeff Klauk 74 70 76 70, Vijay Singh (Fij) 74 70 77 69, Bill Haas 70 75 76 69, Bill Lunde 72 73 72 73, Todd Hamilton 72 68 75 75

292 Boo Weekley 72 70 73 77, Louis Oosthuizen (Rsa) 72 71 76 73

293 Aaron Baddeley (Aus) 75 68 76 74, Richard S Johnson (Swe) 70 74 76 73, Skip Kendall 68 73 75 77, Kevin Streelman 71 72 76 74

295 Brian Davis (Eng) 71 73 76 75, Oliver Wilson (Eng) 72 70 78 75

296 Woody Austin 72 72 76 76

299 Bart Bryant 71 74 75 79