Jordan Spieth missed the cut as fellow American Charley Hoffman took the halfway lead at the Deutsche Bank Championship in Massachusetts.
The Masters and US Open champion made three bogeys and though he finally picked up a birdie at the last hole, a 73 to add to his opening 75 left him six over par for the tournament and outside the three-over cut line.
World number one Rory McIlroy made the cut with only a shot to spare after a 74 left him two over.
McIlroy made four bogeys in five holes on the back nine to finish a disappointing three over for the day as he lost ground on the leaders.
Spieth was joined by England's Justin Rose in missing out on the final two rounds but at the other end of the leaderboard, Hoffman showed there were scores to be made at TPC Boston with a superb eight-under-par round of 63.
He started at the 10th hole and made two birdies in his first four holes before adding three in succession leading into the turn.
A perfect wedge into the second set up another birdie and he picked up further shots at four and five, the latter after a dead-eyed iron approach from 190 yards.
Though he put a lone blemish on his card with a bogey at the eighth, there was still time for one final birdie with a 10-foot put at the last.
The round took him to 12 under for the tournament, three strokes clear of first-round leader Brendon de Jonge who followed up his opening 65 with a three-under-par 68.
Hoffman told PGA Tour Radio: “I got off to a good start on 11, almost made a one, and I kept it going pretty solid on the back nine, which was my front nine.
“I made a good par save on three, a little sloppy bogey on eight but a nice birdie to finish the day off.
“It’s one of those courses that sets up well, the visuals are good, and I tend to make a few more putts than average for me on these greens.
“I just want to have a chance on Sunday. The first two days I’m obviously in a pretty good position but we’ve got a lot of golf left.”
Open champion Zach Johnson shot 65 to share third place with fellow Americans Rickie Fowler and Kevin Chappell and Australian Matt Jones, all on eight under.
The European challenge begins at seven under, courtesy of Ryder Cup star Henrik Stenson and Scotland's Russell Knox. American Sean O'Hair is alongside the pair.
Jason Day, the US PGA champion and bidding to reach number one in the world rankings for the first time, is in a high-class group of players at six under alongside rising stars Danny Lee and Hideki Matsuyama and veteran Jim Furyk.
England's Luke Donald remained four under after a level par 71, with Ian Poulter a shot behind after a 72.
