Tiger Woods racked up the records with a massive eight-shot win in the American Express Championship.

But Padraig Harrington was left to reflect on an opportunity missed as he slid from fifth at halfway to a share of 17th after a closing 73.

It took Woods seven and a half hours to complete an incredible 13th World Golf Championship victory and his sixth strokeplay win on the trot.

Two rain delays delayed the inevitable until after six pm but the result was still the same as Woods carded a four under par 67 to finish eight shots clear of Ian Poulter and Adam Scott on 23 under par.

Not only was it Woods' ninth victory of the year, it was also his fifth American Express victory from seven attempts and his 13th World Championship win from a possible 24.

Harrington had vowed to go after the World No 1 at the weekend by throwing caution to the wind.

But after losing ground with a third round 71, he crashed down the leaderboard on the final day with a tired, two over par effort.

As a result Harrington made only a small dent in the €750,000 that separates him from Order of Merit leader Paul Casey with just two big money events remaining.

The English ace finished 58th in the 60-strong field but still retained his lead at the top of the money list as David Howell could do no better than 13th.

Harrington made an early birdie at the 228 yard fourth, draining a 25 footer to get to 10 under par.

But the birdies dried up after that and the Dubliner dropped three shots coming home as the mental exhaustion of last week's Ryder Cup victory took its toll.

Woods, on the other hand, made up for his first round loss in the HSBC World Matchplay and the debacle of the Ryder Cup with yet another imperious victory.

After playing seven of the last nine weeks, Woods said: "We had it all with the weather today - all we didn't have was snow. It was just a day of patience and not making any bogeys. I made one, unfortunately.

"I'm looking forward to getting in the water, going diving and getting away from the game for two weeks. I'm a little fried."

That dropped shot came at the par four 12th but by that stage the world No 1 had already made three birdies and he completed a comfortable win by picking up two more at the 15th and 18th.

Ryder Cup hero Darren Clarke closed with a one under par 70 to share 26th place on three under par.

Just 24 hours earlier, the Dungannon man revealed how David Beckham had made his weekend by sending him three signed Real Madrid football shirts, one each for himself and his sons Tyrone, 8, and Conor, 6.

Clarke said: "I think it's a fantastic gesture from somebody I've never met. It shows what a great guy he is to go out of his way to do something like that."