Master champion Charl Schwartzel joined Bubba Watson and Australia's Adam Scott in a three-way tie for the lead at the halfway stage of the Deutsche Bank Championship on Saturday.
Watson, playing in the morning when conditions were ideal for low scoring, grabbed the early clubhouse lead when he a shot a 64 to reach 10-under and was then joined by Schwartzel of South Africa and Scott, the joint runner-up at Augusta this year, in the afternoon.
The trio ended the day one shot ahead of Brandt Snedeker, who aced the par-three 16th hole, and two clear of Nick Watney. Five players, including Ernie Els, were bunched together at seven-under on a condensed leaderboard.
Scott shot a 63, the best round of the day, after a bogey-free round featuring six birdies and an eagle.
Schwartzel shot a 66 for the second day in a row. The South African made seven birdies, including six in a seven hole stretch, and two bogeys.
Snedeker hit a nine-iron from 146 yards for his hole in one then drained a 21-foot putt on the 18th for eagle in his round of 64 while Watson, a two-time winner on the PGA Tour this season, eagled the par-five seventh hole when he struck his approach from 232 yard to within 12 feet of the hole.
The tournament is the second leg of the season-ending FedEx Cup playoffs. The leading 70 players after Monday's final round move on to the BMW Championship at Cog Hill before the top 30 qualify for the Tour Championship finale at East Lake.