Matt Kuchar extended his lead by a further shot as the second round of The Barclays was completed early on Saturday morning in New Jersey.
Kuchar, who had five holes left to play, mixed three birdies and two bogeys to finish with a 65 that moved him to 11-under-par at the halfway point of the tournament.
The 35-year-old - who has already won twice this season - is now two clear of his closest challengers, Webb Simpson and Gary Woodland.
"I was kind of hoping for nice, still conditions this morning, and some really good scoring conditions," said Kuchar. "And 15, 20-mile-an-hour (winds, it was a little more challenging."
Tiger Woods, playing in the same group as Kuchar, missed a 13-foot putt for birdie when play resumed at the 14th, but did add a birdie the 17th to improve to six-under-par, five shots off the pace.
Charl Schwartzel eventually signed for a second-round 67 to reach seven-under 135 which moved him alongside reigning Masters champion Adam Scott, 2011 PGA champion Keegan Bradley and Rickie Fowler.
Meanwhile, Rory McIlroy posted a 65 that featured eight birdies to join a group of nine at 136.
The third round of the tournament - which is the first of four FedEx Cup play-off events - was quickly underway after the completion of the second with officials still trying to make up ground lost following thunderstorms on Thursday.