Webb Simpson had six birdies over his last nine holes for a 5-under 66 that made him the clubhouse leader at The Barclays.
Simpson had to play 29 holes Friday as the tournament tries to catch up from six hours of rain delays in the opening round. He made a bogey on the last hole and was at 9-under 133, two shots ahead among half the field that finished the second round.
Keegan Bradley had a bogey-free 68, while Rickie Fowler had a 64. Adam Scott was tied for the lead at one point until a bogey on the last hole gave him a 66. They were in the group two shots out of the lead.
Phil Mickelson had a 69 and was seven shots behind.