Mark Kuchar holds a one-shot lead after carding a second round six-under-par 65 at The Barclays in New Jersey.
Dustin Johnson and Vijay Singh are one shot behind after rounds of 63 and 64 respectively.
However, the spectre of Hurricane Irene and its impending arrival has been hanging over the event and tournament officials have confirmed it has been reduced to 54 holes.
The plan is for the third and final round to start this morning in the hope it can be concluded before the rain arrives.
If not, it will revert to a 36-hole tournament.
Kuchar wasted no time in heading to the top of the leaderboard on 14 under, with a bogey-free round that included six birdies.
The American said: “The best players generally come out winners after 72, so for me, I feel like the more golf we play, the better my chances.
“But, given the situation, I love being on top of the leaderboard with 18 holes to go.”
Johnson also enjoyed a bogey-free round and sunk eight birdies for an eight-under-par 63 as did Singh although he did have a bogey for a seven-under-par 64.
Jonathan Byrd is one shot further back after a 66 with England’s Justin Rose and Ireland’s Padraig Harrington in a four-way tie for fifth along with Aaron Baddeley and Charley Hoffman.
Harrison Frazar and William McGirt, overnight leaders alongside Kuchar, were in a three-way tie for ninth after both carded rounds of two-under-par 69.