Tiger Woods produced a late night, made-for-TV special to snatch the Arnold Palmer Invitational with a dramatic 72nd hole birdie as cameras flashed in the packed Bay Hill gallery.

In a state where Disneyland and Universal Studios make fantasy a reality, Woods came from five strokes behind Sean O'Hair to win his 66th PGA Tour title by a shot and avoid what he described as a potential "dawn patrol" play-off.

And he did it with a stunning performance that left NBC patting themselves on the back for opting to clear their planned early evening prime-time schedule to show what turned out to be a jaw-dropping finish.

Playing only his third tournament since returning from reconstructive knee surgery, Woods completed a record sixth victory at Bay Hill Club by dramatically sinking a 16-foot birdie putt on the final hole in fading light, matching the biggest final-round comeback of his PGA Tour career.

Padraig Harrington briefly occupied third place, getting to within three shots of the lead after two early birdies, before being forced to settle for a share of 11th place on one-over par after carding a level par 70 that featured disappointing bogeys at the 16th and 18th.

Ulsterman Graeme McDowell dropped four shots in his last six holes for a 74 that relegated him from 24th to tied 40th on seven-over.

Woods finally caught O'Hair by draining a 30 foot birdie at the par-four 15th and claimed the outright lead for the first time when his playing partner bogeyed the 16th after hitting his approach into water. Woods saved par there by hitting a 100 yard wedge shot to three feet.

Although Woods stumbled on 17, where his tee shot ended up under the lip of a greenside bunker, he calmly rolled in the 16-footer on the 18th green for a five-under total of 275.

Woods celebrated with a trademark uppercut as the ball tracked into the middle of the hole and then hugged his caddie Steve Williams, who lifted him off his feet.

He said: "It feels really good. 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 but it kind of felt good."

O'Hair, who had been bidding for a third PGA Tour title, had to settle for second place after closing with a 73 with 2007 Masters champion Zach Johnson (69) a further two strokes back at two under.

The start of the final round was delayed by an hour and 45 minutes due to the threat of lightning after storms rolled into the area earlier than expected, forcing NBC to make a decision on whether or not it would stay for the late finish. They did and it proved to be an inspired decision as the battle between Woods and O'Hair grew more gripping with every passing hole.

The world No 1 began to eat into O'Hair's lead with a towering iron to six feet setting up a two at the second and then followed that with a birdie to his opponent's bogey at the third. Suddenly the gap was just two.

A bogey by Woods at the fourth gave O'Hair some respite but the young American was showing signs of weakness and threep-putted the par three seventh as Woods made another two to cut the gap to just one stroke.

O'Hair did well to steady the ship after that but must have sensed what was coming as Woods saved an incredible par from 15 feet at the 14th where he was plugged under the lip of a greenside bunker.

Then at the 15th the huge crowd went wild as a 30-foot birdie putt from Woods died into the centre of the hole and meant he had drawn level for the first time all day.

At the 16th Woods went ahead for the first time, getting down in two from 80 yards while O'Hair made a terrible mistake from the middle of the fairway, finding the water with his approach. 

A Woods bogey at the 17th, where he was plugged under the lip of a bunker again but failed to rescue his par on his occasion, set up a dramatic finish and Tiger did not disappoint.

Harrington moved up the leaderboard with birdies at the fifth and sixth but paid dearly for some poor driving.

A bogey at the ninth, where he had to lay up after pushing his tee shot into sand, effectively ended his remote chances of making a charge for the title.

And while he birdied the 10th to get to within sight of a top three finish, errant drives at the 16th and 18th forced him to lay up twice more and cost him two vital shots.

As he prepares for his final Masters warm up in the Shell Houston Open, the Dubliner will still be encouraged with his best finish of the season on the PGA Tour and his second best this year following his fifth place in Abu Dhabi in January.

He will also be pleased that Woods is now an even hotter favourite for the Masters title, leaving him out of the spotlight's glare.

Ominously, Woods won without producing his best form from tee to green.

He said: "It feels great to be in contention again, to feel the heat on the back nine. And then obviously the big bonus is to win a golf tournament. It's always nice to win a tournament pre-Augusta, and I was able to do that again this year."