St. Andrews. - The British Open began Thursday morning under threatening skies with a tee shot by 1999 champion Paul Lawrie of Scotland.

Light rain started falling about an hour later, and an even more ominous storm was bearing down on St. Andrews as some top players prepared to tee off.

Tiger Woods won at St. Andrews in 2000 and 2005, and he's again a heavy favorite as golf's oldest major returns to the birthplace of golf. The world's No. 1 player has yet to win since returning in April from a five-month layoff stemming from scandalous reports that he cheated on his wife with multiple women.

A steady rain soaked the course on Wednesday, forcing officials to postpone the Champions' Challenge. Twenty-six former winners were scheduled to play a four-hole exhibition, with the winning team earning $76,000 for its designated charity. The money went to Seve Ballesteros' foundation, honoring the former champion who's battling brain cancer.

Lawrie, who rallied to win at Carnoustie after Jean Van de Velde's epic meltdown on the 72nd hole, opened with a tee shot down the middle toward the famous Swilcan Burn. John Daly, the surprising winner at St. Andrews in '95, birdied the first two holes and was among the early leaders with 55-year-old Loren Roberts and Germany's Marcel Siem.

With speculation about his private life swirling around, Woods was to tee off mid-morning - not long before the heavy rains were projected to arrive - in a group that includes English favorite Justin Rose, who has won two of his last three PGA Tour events and is trying to become the first British golfer to win the Open since Lawrie.

Woods has 14 major titles, just four off the career record held by Jack Nicklaus.

Playing in the group right behind Woods and Rose will be two-time champion Padraig Harrington of Ireland, looking for his first sanctioned tournament win since capturing a third major title at the 2008 PGA Championship. Harrington is joined by 60-year-old Tom Watson, who nearly became golf's oldest major winner at Turnberry a year ago.

Watson would have claimed the claret jug for the sixth time if he had made an 8-foot putt on the 72nd hole. Instead, he lost in a four-hole playoff to Stewart Cink.

The defending champion will be playing the first two rounds with Ernie Els of South Africa and Ian Poulter of England.

Woods has been atop the world rankings for more than five years, but Phil Mickelson can take over the No. 1 ranking for the first time in his career if wins this week. Mickelson captured his third Masters title in April, contended at the U.S. Open and believes his long-hitting game sets up well for the Old Course. - Sapa-AP