PGA champion Justin Thomas made three long birdies on a long, wet TPC Boston for a tournament-best 63, giving him a share of the lead with Marc Leishman going into a Labor Day finish in the Dell Technologies Championship.
Leishman also played bogey-free Sunday and had three straight birdies on the back nine for a 65.
They were at 12-under 201 with no room for error on a leaderboard that was packed with some of golf's best players.
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Paul Casey, who played in the final group last year at TPC Boston, shot 67 and was one shot behind. Jordan Spieth birdied his last two holes and was among those two shots back.
Not to be forgotten was Dustin Johnson, who birdied four of his last five holes and was three behind.