Mack Beggs, a junior at Euless Trinity High School in the Dallas-Fort Worth area, won a regional championship after two opposing wrestlers forfeited, apparently over concerns that Beggs has an unfair advantage because of testosterone treatments that are part of the transition.
Beggs, who has a 53-0 record, won his first match of the day, beating Taylor Latham 18-7.
Beggs was born a female, which is stated on his birth certificate. State rules require him to wrestle girls in his same weight class.
"She should wrestle with the boys, is the way I feel," said Dumas High parent Isaac Gomez.
His transition is causing outrage among some parents who say the testosterone therapy Beggs is given to become male gives him an unfair advantage. Lisaann Crixell, whose daughter could wrestle against Beggs, calls that a concern.
"My only concern for my daughter is that she is not out gunned by the testosterone," Crixell said.
Attorney Jim Baudhuin unsuccessfully sought an injunction before the district and regional meets, seeking to prevent Beggs from wrestling during the transition.
Baudhuin now blames the state's governing body for public school athletics and a vote a year ago by school superintendents and athletic directors that required athletes to compete under the gender on their birth certificates.
Baudhuin said his outlook changed because he said he read reports that Beggs had asked the governing body, the University Interscholastic League, to compete as a boy and was turned down. Baudhuin couldn't confirm that account, and the UIL declined to discuss the specifics of Beggs' case.
The UIL has a policy that allows banned substances for medical reasons. Beggs' school district says it shared the athlete's medical records with the UIL and that the testosterone is "well below the allowed level."
"The more I learn about this, the more I realize that she's just trying to live her life and her family is, too," Baudhuin said of Beggs. "She's being forced into that position. Who knows, through discovery we may find out that's not the case. But every indication is, the way the winds are going now, the blame rests with the UIL and the superintendents."
Many support Beggs and the courage, determination and focus they believe it's taken him to make the journey to state finals not just as an athlete, but as a human being.
"To stand up and say 'hey this what I am, my choice and this is what I love to do.' To me everyone should take their hat off and applaud the child," said parent Corey Harris.
Trinity's wrestling coach, Travis Clark, referred all comment to the school district spokeswoman. Phone calls to Beggs' grandmother and guardian, Nancy Beggs, rang unanswered and no one answered the door Wednesday at an address listed for her.
A year ago, superintendents and athletic directors voted overwhelmingly to require Texas public school officials to use a birth certificate to determine an athlete's gender, with transgender advocates warning that such requirements would violate the UIL's constitution and federal Title IX laws.
The UIL defended its rules-making process as "transparent" and a reflection of the public across more than 1,400 member schools.
"This open approach has produced rules that reflect views widely held by school districts across the state and are intended to serve Texas students," the agency said.
Chris Mosier, the first openly trans athlete to make a U.S. men's national team when he qualified in the duathlon in 2015, said Beggs' case could lead to change, perhaps even without a lawsuit.
"Mack is challenging what people thought was a good policy," said Mosier, founder of TransAthlete.com. "This very well may spark change from people just by seeing how the policy was not well thought out and this is the outcome of following the rules exactly as they are."
Texas is one of seven states that require high school students to provide a birth certificate, proof of gender-reassignment surgery or documentation of hormone therapy, according to TransAthlete.com. It says other states like California and Florida have more inclusive rules.
Under NCAA rules, athletes transitioning from female to male are allowed to compete on men's teams while taking testosterone, but can't compete on women's teams.
That's what Baudhuin said he wants in Beggs' case, saying he would rephrase parts of the lawsuit to emphasize excluding Beggs from competing against girls rather than banning Beggs from competing at all.
"Mack is a great kid, hard-working, great kid," Baudhuin said. "So this is not personal. This is not a hatred issue. We just don't think it's fair that Mack should wrestle, either be allowed or should be required to wrestle, against girls."
Baudhuin said he would not seek a last-minute injunction to keep Beggs from competing at state, but did say he plans to pursue his lawsuit after the season is over. The attorney envisions the same scenario in December, when Beggs' senior wrestling season starts. And Baudhuin wonders about other sports.
"What if next year it's a swimmer and the year after that it's somebody who's running track or somebody playing basketball or whatever?" he said. "This isn't the one and only time that there's going to be a transgender athlete involved."
A change to the UIL policy would require a committee's recommendation that would then be sent to the larger membership for a vote. It's too late for that process to affect Beggs' senior season, and the odds are against it in a state that is considering legislation that would require people to use the bathrooms that correspond to the gender on their birth certificates.
The Associated Press contributed to this report.