Three players share the lead at ten-under-par after the first two rounds of the Deutsche Bank Championship in Boston.
Adam Scott shot the day's low round, an eight-under 63, to join Masters champion Charl Schwartzel and American Bubba Watson atop the leaderboard.
Scott, who won last month's World Golf Championships event at Akron, made six birdies and an eagle on the TPC Boston course.
The 31-year-old Aussie said: "That was a really solid round. I turned it around with the putter after a balky day on the greens yesterday. I'm happy to be back in the mix again."
England's Luke Donald started the second round just a shot off the pace but the world number one slipped back into a tie for 11th, four shots back, after only managing a one-under 70.
The event is the second of four tournaments in the lucrative FedEx Cup play-offs.