Ayrshire, Scotland (My Sportsbook) - Tom Watson surely has grown to love the British Open. He has won eight British Open titles - five on the regular tour and three Senior British Opens.

Watson, who missed the cut last year at Royal Birkdale, returned to Turnberry with plenty of good memories. He defeated Jack Nicklaus in 1977 in the famous "Dual in the Sun" at this week's host course and also claimed the Senior British Open at Turnberry in 2003.

The 59-year-old posted a bogey-free round of five-under 65 to lead the Open Championship by a stroke. The 65 was Watson's lowest first-round score in his career.

His best previous first-round score in the Open Championship was 67. He did that twice, first in 1983 at Royal Birkdale, where he won, and then again in 1995 at the Old Course at St. Andrews.

Watson got off to a fast start with birdies on one and three. Playing smart major championship golf, Watson ran off six consecutive pars from the third to turn in minus-two.

Around the turn, Watson rolled in another birdie try on the par-four 10th. He moved to four-under with a birdie on the par-four 12th.

Watson, whose best recent finish was a tie for 18th in 2003 at Royal St. George's, connected on his final birdie at the 17th. That gave him the lead at minus-five, and Watson two-putted for par at the last.

If Watson were to remain the leader, he would be the oldest man to lead any of the four major championships after the first round.

On the regular tour, he last led a major after the first round in 2003, when he shared the first-round lead at the U.S. Open before finishing tied for 28th. His last first-round lead in the British Open was in 1995, where he struggled in the second and final rounds and fell into a share of 31st.

Watson won his five British Open championships at Carnoustie, Turnberry, Muirfield, Royal Troon and Royal Birkdale. On the Champions Tour, his victories were at Turnberry, Royal Aberdeen and Muirfield.