Ryan Armour, Bronson Burgoon, Mackenzie Hughes, Abraham Ancer, Kyoung-Hoon Lee and Zack Sucher shared the first-round lead at 6-under 64 on a rainy Thursday at the Travelers Championship. Paul Casey, who gave up a four-shot lead in the final round a year ago, topped the group at 65. Two-time champion Phil Mickelson shot a 67 and Brooks Koepka, coming off his runner-up finish in the U.S. Open, had a 71.