In what might be the most controversial high school wrestling victory ever, a transgender boy completed an undefeated season Saturday by winning a Texas state girls’ wrestling title.

Mack Beggs, 17, was born female but has been undergoing a testosterone treatment for more than a year and currently has the muscle mass of a similarly-aged male, The Fort Worth Star-Telegram reported. Though Beggs, a junior at Euless Trinity High School, would prefer wrestling boys, state policy dictates that athletes must compete as the gender listed on their birth certificate. The result: A 56-0 season and 110-pound weight class title.

“The overwhelming sentiment here is that Mack should be allowed to wrestle, but should be required to compete against the boys,” said attorney Jim Baudhuin, who filed a lawsuit to ban Beggs from the girls division next season. Baudhuin is the parent of a wrestler at another school, The Associated Press reported.

Beggs’ parents said their child has identified as a boy since age 3, The Star-Telegram reported, and transgender experts who spoke to the paper said the rule requiring Beggs to wrestle girls is wrong.

“Wanting him to compete with girls is going against best practices and guidelines that are already established by organizations like the NCAA,” said Dr. Robert Garofalo, of Chicago’s Lurie Children’s Hospital.

Despite criticism of the policy, University Interscholastic League executives don't envision a change.

“Ninety-five percent of the school superintendents in Texas voted for the rule as it was proposed, which was to use birth certificates,” UIL deputy director Jamey Harrison said. “So any rule can be reconsidered, but…given the overwhelming support for that rule, I don't expect it to change anytime soon.”

Beggs, who beat Chelsea Sanchez, 12-2, to win the state title, avoided talking about the transgender topic and instead tried to shine a light on the teammates who were also competing.

“I wouldn't be here today if it weren't for my teammates,” Beggs said. “That's honestly what the spotlight should have been on is my teammates. The hard work that I put in in the practice room with them, beside me — we trained hard every, single day. Every, single day and that's where the spotlight should have been on. Not me. All of these guys. Because I would not be here without them.”

The Associated Press contributed to this report.