American Bubba Watson leads The Barclays at the half-way point on -7 after shooting a second round 68 on Friday.
The 36-year-old, who won the Travelers Championship for a second time this season, fired in four birdies and two bogeys for a two-under-par score to hold the outright lead in New Jersey.
The three-time Ryder Cup participant looked in good form at Plainfield Country Club and is one stroke ahead of the field as he aims for an eighth win on the PGA Tour.
There is a four-way tie for second place with the American trio of Tony Finau, Zach Johnson and Jason Dufner joined by Sweden’s Henrik Stenson on -6.
The latter, who has endured a frustrating season so far, fired in five birdies and just the one bogey for a four-under-par 66 and is in contention for a first win since clinching the 2014 DP World Tour Championship.
American Jason Bohn and Colombia’s Camilo Villegas are a further stroke behind on -5 with the former hitting a sensational six-under 64, rising 52 places up the standings.
Elsewhere, US PGA champion Jason Day, who was an injury doubt before the tournament, is in a seven-way tie for eighth on -4 after the Australian hit a second consecutive round of 68.