U.S. Open: Hunter Mahan says tough day at Merion will benefit him - Article Photos 1/1

Hunter Mahan reacts after a putt on the 13th hole during the fourth round of the U.S. Open golf tournament at Merion Golf Club, Sunday, June 16, 2013, in Ardmore, Pa. (AP Photo/Morry Gash) ORG XMIT: USO242