Jake Knapp shot an 11-under 61 to break a Rocket Classic record that stood for less than a day, becoming the first PGA Tour player to break 60 and shoot a 61 or lower in the same season.
Padraig Harrington made four birdies Thursday, though it was the bogey he saved on the 15th hole that helped him keep a share of the first-round lead with Mark Hensby at the U.S. Senior Open.