LOUISVILLE - There is a three-way tie atop the leaderboard after the first round of the PGA Championship. Lee Westwood, Kevin Chappell and Ryan Palmer each shot a six-under 65 on Thursday. They lead a pack of five other golfers by one shot, including world number-one Rory McIlroy. Phil Mickelson opened with a two-under 69 to sit in a tie for 20th. Tiger Woods struggled to a three-over 74. He declared himself pain-free and ready to go after a practice round on Wednesday. Woods withdrew from last Sunday's final round of the WGC-Bridgestone Invitational with back spasms, putting his status in doubt.