The top seeded junior had just won the first set, 6-0, and looked well on her way to capturing her first district crown.
Then, it happened.
A string broke on her racket, forcing Wagner to go to a backup.
"I shouldn't have let it get to me, but I guess I kind of did," Wagner said. "I don't have the same racket as my other one. I just wasn't as comfortable."
Kamprath, the No. 3 seed, responded by getting back into the set, gaining a 5-4 advantage.
But, that would be the final point Kamprath would get as Wagner settled in and won the final three points en route to a 6-0, 7-5 victory at Hershey Racquet Club.
Last year, Wagner finished fourth in the district tournament, one spot out of advancing to the PIAA tournament.
"Coming back this year, I knew I wanted to get into the top three," Wagner said. "I managed to do that luckily."
Just how did Wagner celebrate such a great accomplishment? She went to powder puff football practice.
"I did not really celebrate," Wagner said. "My parents wanted to go out to dinner, but I really want to be in this (powder puff) game, so I need to go to practice."
Wagner advanced to the championship match with an inspired performance against Mechanicsburg's Nicole Coons in the semifinal round, winning 7-6 (4), 7-6 (7).
"It was a tough match. Katie's timing was a bit off," Susquehannock head coach Marianne Michels said. "Nicole got to everything."
Wagner added, "I wanted to start off strong, but I got a little behind. I just wanted to get ahead right away in the tiebreaker. I think in both of them I got up and I used that to my advantage."
That victory propelled Wagner into the championship match, which is something the three sport athlete couldn't have imagined happening when she began playing the sport around eight years ago.
"My mom played tennis in high school and she kind of brought my sister and me up on it," Wagner said. "I realized I loved it."
Wagner added the district title to her collection, which includes two YAIAA singles titles.
"They're both equally as important," Wagner said of the district and league crowns. "In districts there are even more people, so it feels like even more of an honor."
Wagner has been in the finals of the YAIAA singles championship the past three years, winning two of them.
"She's come so far," Michels said. "Every year, she's just gotten better and better. She's taken the experience of every match and has utilized it."
Wagner will lead the Warriors in team districts today at Hershey Racquet Club. Susquehannock, the No. 5 seed in Class AAA takes on top seeded Hershey at noon in a semifinal.
Following team districts, Wagner will get to take the next step of her tennis career to the state level.
As the top seed in District 3, Wagner will face off against the No. 1 from District 9. The first round is scheduled for Nov. 1 at noon at Hershey Racquet Club.
"I really don't know what to expect," Wagner said. "I'm just going to try my best. Just try to take it round by round."