David Frost sits one stroke behind in second, with Fred Couples right behind Frost in third.
Kenny Perry shot a 3-under 68 to settle in eighth after one day in his quest to take home the Charles Schwab Cup as the season’s best player. He needs to finish in the top five or hope Bernhard Langer, with whom he was paired Thursday, does not take first in order to retain the points lead for the year.
For Senior, the day marked what he called his best round of the year as he seeks his first win of the season.
“I had a pretty good start to the year,” he said. “But the last couple of months have been pretty poor. ... I just started to hit a little better last week. It’s just nice, it doesn’t matter when it is, to put a round together like this.”
Senior’s round matched the best first-round score in Charles Schwab Cup Championship history and also matched his lowest round ever on the Champions Tour — equaling his total from the second round of the 2012 Senior PGA Championship. In 2003 at the Sonoma Golf Club, Jim Thorpe shot a 63 in the first round and went on to win the event by three strokes.
Frost felt he was in the groove early as he birdied three of the first four holes of the day, but he kept things in perspective.
“I said to my caddie going down to the fourth hole, ‘Gee, there’s a lot of golf left to be played,’” he said. “Since we’re on the fourth hole and there’s four rounds to play. You want to get excited but there’s so much golf to play. You can’t get ahead of yourself just because you had a couple of birdies in the first few holes or for that matter had a great front nine. There’s a lot of golf to be played out there.”