ARDMORE, Pa. -- Jason Dufner matched the low round of the week with a 67 Sunday at Merion Golf Club.
Now he'll see if it's good enough to win the U.S. Open.
Dufner and ernie Els are the clubhouse leaders at 5 over with the final groups just now hitting the back nine. Els shot 69.
Five others are ahead of them on the leaderboard at the moment, but players have struggled mightily with Merion's closing holes.
No one is under par at the moment with Jason Day, Justin Rose and Hunter Mahan leading at 1 over.
Phil Mickelson, who had the lead at the start of the day, is a stroke back after playing his first nine holes in 3 over. A five-time runner-up in this U.S. Open, Mickelson continues to burn the edge of holes with his putts.
Meanwhile, Rickie Fowler and Billy Horschel are both at 4 over.