Jay Haas matched the Champions Tour record with a 10-under 60 to take a five-stroke lead in the Charles Schwab Cup Championship.
The 58-year-old Haas made a 5-foot birdie putt on the par-5 18th after hitting his second shot into a greenside bunker and leaving his eagle blast short. He is 14 under for the tournament.
Haas became the eighth player in the history of the 50-and-over tour to shoot 60, breaking the course record on Desert Mountain's Cochise layout.
Tom Lehman was second after a 63, moving into position to win the season-long Charles Schwab Cup points race. Bernhard Langer, 211 points ahead of second-place Lehman, was tied for fifth at 6 under after a 65.
Fred Couples was third at 8 under after a 66.