Tiger Woods felt he had proved the doubters wrong after maintaining his incredible record in World Golf Championship events with victory in the American Express Championship in San Francisco.

Woods defeated John Daly on the second play-off hole after the pair had finished tied on 10 under at Harding Park.

After both players parred the 18th in sudden death the world number one left his birdie putt on the 16th inches short of the hole, and then watched as Daly three-putted from 18 feet.

It gave Woods his fourth American Express title in six attempts, his 11th win in 21 World Golf Championship events, and took his earnings to £7.7million in WGC events alone.

The 29-year-old took his tally of majors to 10 with victory in the US Masters and Open championship, despite starting the year with question marks over his decision to change his swing with coach Hank Haney.

"It turned out to be a great week. I didn't really have my best stuff this week but I hung in there with my mind and hit some good shots when I needed to," said Woods.

"All the naysayers who said that I was doing the wrong things, they can understand now why I made those changes. I was building, this is part of the process I went through the last couple of years, changing my game and working to get to a point like this.

"Each and every week I feel as if I just play my game I should have a chance come the back nine and that's where you want to get to."

Daly held a one-shot cushion overnight and was still one ahead with two to play despite Woods making a typical charge with a hat-trick of birdies from the 10th.

But the former Open champion then three-putted the 17th for bogey and repeated the error on the second extra hole to miss out on his biggest win since victory at St Andrews in 1995.

"I thought I had it but I missed a birdie putt on the 16th and then missed from four feet on 17 and that was the golf tournament," said Daly. "I should have had it won but it's just a lack of confidence in putting.

"Tiger has won so many golf tournaments I am sure I was feeling a bit more heat than he was but you just hate to lose that way and I know Tiger hates to win that way."

Meanwhile Colin Montgomerie moved closer to an incredible eighth Order of Merit title despite narrowly missing out the play-off.

Montgomerie missed a number of birdie chances on the back nine before eventually holing from 12ft on the 17th to lie just one shot off the lead, but a bogey on the 18th dropped him from outright third into a tie with Sweden's Henrik Stenson and Spain's Sergio Garcia.

The 42-year-old Scot, who won his first title for 19 months in the Dunhill Links last weekend, had the consolation of moving around £90,000 ahead of US Open champion Michael Campbell in the money list with three events remaining.

Montgomerie, who fired a closing 70, said: "I played great on the back nine and got nothing out of it. I hit some great shots in there and played it level par. It's disappointing really but I would have taken third before we came so that's okay.

"The last hole is dead against me. If I was to build a golf hole I would build it the other way. It's a hooker's hole and I'm a fader.

"I am very tired now but I have done okay. I came here to try to do a few things and I achieved them. I am coming away very positive and can take it on next week in Madrid.

"It feels fantastic to go top of the Order of Merit. I had a goal at the start of the week to overtake Michael and get some more Ryder Cup points, which I achieved."

England's David Howell continued his superb run of form with a final round 67 to finish five under alongside Ulsterman Graeme McDowell.

"I am pleased with my week's work but a bit disappointed," said Howell. "I got myself to seven under and if I had had a good strong finish I could have posted a good total."

Collated final-round scores (Gbr&Irl unless stated, Par 70):

Woods wins at second extra hole

270 Tiger Woods (USA) 67 68 68 67 (£734,629), John Daly (USA) 67 67 67 69 (£423,824)

272 Henrik Stenson (Swe) 70 67 67 68, Colin Montgomerie 64 69 69 70, Sergio Garcia (Spa) 67 69 67 69 (£199,856 each)

275 David Howell 67 67 74 67, Graeme McDowell 69 70 68 68, Vijay Singh (Fij) 67 70 69 69, David Toms (USA) 68 68 70 69

276 Stephen Ames (Can) 72 64 71 69

277 Shigeki Maruyama (Jpn) 74 69 67 67, Davis Love (USA) 71 68 71 67, Luke Donald 70 71 68 68, Stuart Appleby (Aus) 71 65 69 72

278 Fred Couples (USA) 74 69 66 69, Chad Campbell (USA) 67 70 70 71, Jim Furyk (USA) 68 67 71 72

279 Charl Schwartzel (Rsa) 72 66 74 67, Mike Weir (Can) 73 67 70 69, Tim Clark (Rsa) 69 69 72 69, Bradley Dredge 69 69 72 69, Ian Poulter 67 70 72 70, Stephen Dodd 70 68 70 71, Angel Cabrera (Arg) 69 66 72 72

280 Mark Calcavecchia (USA) 67 68 74 71, Brandt Jobe (USA) 68 71 71 70, Yasuharu Imano (Jpn) 69 68 72 71, Billy Mayfair (USA) 69 67 73 71

281 Fred Funk (USA) 67 68 75 71, Phil Mickelson (USA) 71 69 73 68, Adam Scott (Aus) 68 70 69 74

282 Kenny Perry (USA) 76 69 69 68, Vaughn Taylor (USA) 71 72 66 73, Jason Bohn (USA) 70 68 70 74

283 Paul McGinley 73 65 72 73, Sean O'Hair (USA) 68 67 71 77

284 Niclas Fasth (Swe) 70 70 73 71, Peter Lonard (Aus) 73 71 69 71, Olin Browne (USA) 67 74 73 70, Ben Crane (USA) 70 68 76 70

285 Miguel Angel Jimenez (Spa) 69 70 73 73, Rod Pampling (Aus) 67 71 76 71

286 Simon Yates 73 68 70 75, Zach Johnson (USA) 68 69 74 75, KJ Choi (Kor) 70 71 72 73

287 Justin Leonard (USA) 75 72 71 69, Stewart Cink (USA) 70 72 75 70, Kenneth Ferrie 74 67 71 75, Michael Campbell (Nzl) 71 68 72 76

288 Joe Ogilvie (USA) 71 74 68 75

289 Jyoti Randhawa (Ind) 70 70 74 75, Nick Dougherty 71 74 72 72, Richard Green (Aus) 69 74 76 70, Jose Maria Olazabal (Spa) 72 72 76 69, Lee Westwood 71 75 75 68

290 Bart Bryant (USA) 71 76 71 72, Mark Hensby (Aus) 72 74 71 73, Nick O'Hern (Aus) 75 69 71 75

291 Gavin Coles (Aus) 71 74 75 71

292 Thongchai Jaidee (Tha) 73 72 73 74

293 Tom Lehman (USA) 73 74 72 74

294 Scott Verplank (USA) 72 69 76 77, Euan Walters (Aus) 74 72 75 73

295 Chris Di Marco (USA) 71 75 73 76, SK Ho (Kor) 72 77 71 75

297 Ted Purdy (USA) 71 75 75 76

299 Padraig Harrington 74 72 80 73

303 Neil Cheetham 77 78 72 76

306 Warren Abery (Rsa) 80 77 75 74

Withdrawn: Thomas Bjorn (Den)