Julia Potter won the U.S. Women's Mid-Amateur on Thursday at Biltmore Forest, beating Margaret Shirley in 19 holes to become the first left-hander to win a USGA female event.The 25-year-old Potter, a recently reinstated amateur from Granger, Ind., is a former University of Missouri player who spent two years on the Symetra Tour and now works as a professional event coordinator. Her father, Phil Potter, caddied for her."It feels incredible," Potter said. "I think it's anybody who plays competitive golf's goal to win a USGA championship, and to be able to do it and to do it here at Biltmore Forest, it means the world to me."I think speaks to anybody. You just have to keep trying. You just never know when you're going to find that course or that week that everything is just kind of working for you like I did this week."Potter saved par on the 18th to remain tied, hitting to a foot from a greenside bunker."I had a good lie in that bunker. I was actually hitting uphill and into the wind, so I knew that would help stop the ball," Potter said. "All I needed to do was land it on the fringe or just on the green and let it trickle down, and that's what it did."The 27-year-old Shirley, from Roswell, Ga., had a chance to win, but her 15-foot birdie try stopped short."I hit a great shot into 18," Shirley said, "but I couldn't get too cute with that birdie putt."On the 19th, Shirley sent her approach into the creek fronting the green, and Potter lagged her putt to 6 inches for a conceded par and the victory."I wasn't watching a lot of Margaret's shots at the end, just kind of basing it off the reaction," Potter said. "I heard the shot and then I heard the reaction, and I knew it happened, and I felt awful for her. That's really not how you want to win, and we had played such an incredible match up until that point."Potter became the third stroke-play medalist to win the title, joining Carol Semple Thompson (1990) and Ellen Port (2000).Shirley played at Auburn and works for Atlanta Junior Golf."I played some of the best golf I've ever played," Shirley said. "It just didn't end the way I wanted it to."The event is limited to players 25 and older.