Timonium, MD (My Sportsbook) - Tom Watson doubled his lead to four shots Saturday with a course record-tying six-under 64 at the Senior Players Championship.

Watson, trying to win this senior major for the first time, carded his second consecutive bogey-free round and moved to 12-under 198 after three rounds at Baltimore Country Club.

The 60-year-old Hall of Famer has gone 41 holes on the East Course without dropping a shot, and even those closest to him on the leaderboard know how tough it will be to catch him.

"He put us pretty far back. I think we're going to have to go all-out tomorrow," said Loren Roberts, who was tied for second place after shooting a 65.

John Cook (65) and Mark Wiebe (66) joined Roberts at eight-under 202, while Jay Haas (67) stood another shot further back at seven-under 203.

Phil Blackmar also fired a 64 Saturday to move into a share of sixth place with Morris Hatalsky (66) at five-under 205.

Watson and Blackmar tied the course record set by Tom McKnight in 2007 and matched by Jeff Sluman last year.

"This golf course sets up pretty well for me," Watson said.

That much has been obvious.

With laser like approach shots and a steady putting hand, Watson, in just his second start since turning 60 last month, scorched the course for six more birdies on Saturday.

Ahead by two shots overnight, he made it look easy again.

Watson's first approach shot -- a nine-iron into the No. 1 green -- set up a close birdie. He rolled in another birdie effort at No. 5 and made a two- footer for birdie at No. 9.

He nearly holed his approach shot for an eagle at the 10th -- the ball took a short hop over the cup -- and tapped in for birdie. He made a 10-foot par save at the next hole to protect a one-shot lead over Roberts.

Watson made his next birdie at the 14th, rolling in an eight-foot putt to extend his lead to two shots. It became three strokes when Roberts was unable to get up-and-down for par ahead at the 18th.

Watson holed a 10-foot birdie putt at the 17th to extend his lead to four.

"There were a lot of good things that went on today. I drove the ball well with the exception of one hole, I hit some good quality iron shots and I made some putts, too," said Watson.

"It was kind of fun."

Less than three months after he lost a playoff to Stewart Cink at the British Open while trying to become the oldest major winner in PGA Tour history, Watson is capturing headlines again.

He is trying to become the oldest winner in tournament history -- Raymond Floyd was 57 years, 10 months and 12 days old when he won in 2000.

Watson, an eight-time major champion on the PGA Tour, is also seeking his sixth senior major title.