Michael Allen tied the Champions Tour record with a 60 to take a three-shot lead after the first round of the Allianz Championship in Boca Raton.
Colin Montgomerie opened his account with a 67 with Roger Chapman 69 and both Anders Forsbrand and Bernhard Langer a 70.
The 55-year-old Allen made an eagle and ten birdies to become the ninth player in the 35-year history of the Champions Tour to shoot 60 and the first to accomplish the feat on a par-72 course.
Allen took advantage of the calm conditions on the Old Course at Broken Sound to grab a three-shot lead over Scott Dunlap. Allen played his last 15 holes in 11 under, highlighted by a 20-foot eagle putt on the 18th -- his ninth hole of the day.
"It seemed really easy," said Allen, who won the 2009 Senior PGA Championship for the first of his five Champions Tour victories.
Allen was fortunate on the par-4 fourth hole when he chunked his approach to the green, then skulled a chip that took two bounces and fell into the hole for an unlikely birdie.
"That's when you kind of think things are going your way," Allen said. "It's great to shoot this round, but if I'm able to win, then it will become even more magical."