Graeme McDowell defeats Tiger Woods in sudden-death playoff

Despite blowing a four-shot lead and his best chance of winning his first golf tournament since his personal life fell apart on a global stage a year ago, Tiger Woods said Sunday he was optimistic about his future.

“Even though I made countless mistakes in the middle part of the round, it said a lot for me to come back and put my swing back together again” late in the round, Woods said after Graeme McDowell beat him on the first hole of a sudden-death playoff Sunday to win the Chevron World Challenge.

“I’m playing well,” said Woods, who led each of the first three rounds. “I’m excited about this off-season. It was a great week even though I didn’t win.”

McDowell, this year’s U.S. Open winner, made a 25-foot putt for birdie on the first playoff hole, the par-four 18th hole at the Sherwood Country Club course in Thousand Oaks.

The players, paired in the final twosome, finished regulation at a 16-under 272 after both made birdie putts on the 18th in the final hole of regulation. This was after Woods gave up the four-shot lead he carried into the final round and after McDowell had blown a one-shot lead with a bogey on the 17th.

Woods, whose poor play earlier this year prompted him to make major changes in his golf swing, effectively lost his way in the middle of the back nine, enabling McDowell to reach him on the leader board.

A key turning point came on the par-five 13th hole, where Woods made a double-bogey seven and McDowell made birdie.

It was the first time that Woods — a winner of 71 PGA Tour events, including 14 major championships — failed to win after starting the last round with a lead of three shots or more.

“To be the guy to break that run is pretty special,” said McDowell, whose win came with a $1.2-million first prize. “It’s definitely another highlight of 2010.”

Englishman Paul Casey matched McDowell’s three-under 69 to finish third at 12 under for the tournament.

The Chevron World Challenge is not a major championship or even an ordinary PGA Tour event. It’s a year-end gathering of only 18 top players that effectively is an exhibition whose main goal is to benefit Woods’ charity, the Tiger Woods Foundation.

But Woods’ comeback had to start somewhere. He hadn’t won since returning to competitive golf at the Masters in April — following the sensational headlines of his extramarital affairs and crumbling marriage began to wane — and he had struggled on golf courses and against rival players he once dominated.

As a result, Woods in late-October was knocked off his perch as the No. 1 player in golf’s world rankings — a position he held for more than five consecutive years — by Lee Westwood.

While the Chevron World Challenge isn’t a formal PGA event, it does award ranking points along with a $5-million purse. But Westwood maintained the No. 1 ranking Sunday by winning a tournament in South Africa, the Nedbank Golf Challenge.

james.peltz@latimes.com