Stallings won the Greenbrier Classic in July 2011 for his first PGA Tour victory. Despite struggling at times during the final round, Stallings was able to earn his way into a three-way playoff. He made a birdie on the first playoff hole, while his opponents, Bob Estes and Bill Haas made par, which gave him the title. The win moved Stallings from 88th in the FedEx Cup standings to 26th. His OWGR ranking went from 224th to 119th, after starting the year at 562nd. The win also qualified Stallings for the 2011 WGC-Bridgestone Invitational, 2011 PGA Championship, 2012 Masters Tournament, and the 2012 Players Championship. Stallings won his second career tournament at the 2012 True South Classic. Stallings was unable to defend his title in Mississippi because he earned a spot in the 2013 Open Championship after an already exempt Phil Mickelson won the Scottish Open. It was the second consecutive major Stallings earned entry as an alternate; he gained entry into the U.S. Open after another player withdrew.