Rory McIlroy carded a 74 in the opening round of The Barclays on a rare disappointing day for the world number one this summer.
The Northern Irishman is searching for his fourth successive victory, but his chances look slim after just 18 holes of the first of four tournaments in the FedEx Cup playoffs.
McIlroy is nine shots behind leader Bo Van Pelt, who is one stroke ahead of his rivals on six-under-par thanks largely to a chip-in for an eagle on the 17th hole.
Six Americans - Ben Martin, Hunter Mahan, Jim Furyk, Brendon Todd, Cameron Tringale and Charles Howell III - are on five-under, alongside Paul Casey and Brendon De Jonge.
Adam Scott is four shots adrift of Van Pelt, while Phil Mickelson, Sergio Garcia and Martin Kaymer could only finish on level-par at the end of day one.