“It just doesn't feel real right now,” said Shirley, who was runner-up to Potter in 2013. “It's obviously the pinnacle of our sport, a USGA championship, and to be able to say I'm a USGA champion now is incredible.”

“I was going to need birdies to beat her,” said Potter, who was trying to become just the fourth back-to-back Women’s Mid-Amateur champion. “I just wasn't knocking them close enough or really sinking putts to be able to put any pressure on her. She played an amazing front nine, an amazing round and she's much deserving of this championship.”

Shirley, 28, of Atlanta, joins Carol Semple Thompson (1997), Ellen Port (2000) and Potter (2013) as the only stroke-play medalists to take the championship title. This also marked the first rematch of championship finalists in Women’s Mid-Amateur history, and made them the third pair of players to meet in back-to-back USGA championship finals.

Shirley struck first, knocking her hybrid approach at the par-4 first hole to 12 feet and holing the birdie.

“That putt kind of got me going for the rest of the round,” said Shirley, a director of Rules and competitions for Atlanta Junior Golf.

Shirley extended her advantage to 2 up with a two-putt par at No. 3. Potter had a chance to halve the hole, but could not convert her comebacker after sending her birdie try long.

Potter pulled within one with a conceded par at the fourth hole. But perhaps the defining moment of the match came at the par-4 seventh. Shirley drained a 25-foot birdie to regain her 2-up advantage and start her championship charge.

“That's actually the first time I've hit that green all week,” said Shirley, who graduated from Auburn University in 2008. “I was just happy to be on that green. And that putt was dead center.”

On the inward nine, Shirley kept putting pressure on her opponent. Potter’s tee shot at No. 10 flew into the right rough, and her second shot clipped a tree and fell well short of the green. Shirley found the left greenside bunker, but converted the up-and-down par for the win and a 3-up lead.

Shirley’s hot hand with the putter again played to her advantage on the par-4 11th. After Potter chipped to within 3 feet for par, Shirley drained an 18-foot birdie putt for a 4-up lead.

Potter had a prime opportunity to end Shirley’s momentum at No. 12. With Shirley’s bogey conceded, Potter missed her short par putt. When Potter missed a par comebacker on No. 13, Shirley had a dormie-5 lead.

“At the end I was trying to push and trying to hit some closer shots,” said Potter, a 2011 alumna of the University of Missouri who works for the Indiana Golf Office. “It didn't work out, and that was really one of the reasons why I missed that putt so badly on 13 was because at that point I need to make. I can't just tie with her.”

Potter won the 14th with a par to extend the match. But after she chipped on well short of the hole at No. 15 and missed her par attempt, she conceded Shirley’s par putt and the championship title.

Families were a weeklong presence for Shirley and Potter. Both players had their father as caddie, and other family supporting from the clubhouse. They each pointed to their father – and their own close friendship that blossomed in 2013 – as the highlights of this championship week.

“Julia is a great champion, obviously a phenomenal player but an even better person,” said Shirley. “We had so much fun out there. It was kind of relaxing this last match. It really was, to play someone that you know.”

“Your father is going to be your biggest support out there,” added Potter. “They're going to believe in you when you don't even believe in yourself. That's what my dad was out there for me, and I'm sure that's the same for Margaret.

“Clearly we have a lot in common and a lot to talk about, but I'm very happy for her and her family to experience what my family and I experienced last year.”

This was the fourth time in championship history that the final match included two players in their 20s, including the 1993 and 1994 finals as well as the Potter-Shirley match in 2013.

Both players needed to finish their semifinal matches on Thursday morning due to torrential rains and storms that halted play on Wednesday. Shirley cruised to a 5-and-4 win over four-time champion Meghan Stasi, while Potter took a 2-and-1 victory over Tara Joy-Connelly.

Shirley receives a 10-year Women’s Mid-Amateur exemption, as well as a two-year exemption into the U.S. Women’s Amateur. Potter receives three-year and one-year exemptions, respectively, but was already exempt due to her 2013 victory.

The U.S. Women’s Mid-Amateur is one of 13 national championships conducted annually by the United States Golf Association, 10 of which are strictly for amateurs. It is open to female amateur golfers who are at least 25 years of age.