Check out Ed Dougherty's Scorecard
At 10-under-par, Dougherty is two shots clear of rookie Ted Goin, who opened in 64. Defending champion Dana Quigley and last weeks runner-up Vicente Fernandez are three back following a pair of 65s at the Tiffany Greens Golf Club.
Dougherty has a pair of top-3 finishes this season. He earned his maiden title last year at the Coldwell Banker Burnet Classic.
Friday, the fourth-year player birdied his first five holes en route to shooting his lowest score ever on the Senior circuit and tying his career low on the PGA Tour.
Goin, who finished 12th in his first attempt at last years Senior Qualifying Tournament, is coming off his best finish of the season. The 51-year-old tied for fifth in last weeks Enterprise Rent-A-Car Match Play Championship, losing to eventual champion Leonard Thompson in 19 holes in the quarterfinals.
A member of the PGA Tour in 1980 and 81, Goin carded five straight birdies beginning at the 4th hole, and added four more to his card for personal best on tour.
Last year, Jim Colbert shot 61 in the first round, but then recorded rounds of 69-71 to finish in third place.
Full-field scores from the TD Waterhouse Championship