Beggs is reportedly on testosterone therapy as he continues to make the transition from female to male, an issue that has sparked some controversy.
Beggs entered the state tournament with a 32-0 record, beating three female wrestlers on his way to the championship.
It was done to help schools determine competition, said Jamie Harrison, the UIL's deputy director. There have been lawsuits filed attempting to bar him from competing against women, and even legislative action that almost passed the state congressional houses.
Beggs' mother, Angela McNew told AP: "He has so much respect for all the girls he wrestles". State law views his injections as being "dispensed, prescribed, delivered and administered by a medical practitioner for a valid medical goal".
Cheers and boos greeted the judges' decision but it confirmed what everybody already knew about Mack Beggs: he is by far the best in his girls' wrestling weight class in Texas.
Many parents have been outraged to see their daughters wrestling someone who, effectively, has the strength of a young man.
Much of the sentiment followed over to his state championship campaign this year, evident in a video of the win which surfaced online, revealing a mix of cheers and boos from the crowd. It states that the state's high school athletics organization, the University Interscholastic League, can "declare a student ineligible for competition on the basis of steroid use" even if the student is taking the substances for "a valid medical goal".
"Last season, two of Beggs' competitors forfeited their meets because they feared being injured", Webster noted.
Despite all the backlash, Beggs entered the ring and capped a flawless 36-0 season.
The opposing coach and teammates had insisted the girl wrestle Beggs, but she refused, McNew said. This year I wanted to prove a point that anyone can do anything. He receives low-level testosterone injections and wants to wrestle against boys.
Beggs wants to wrestle in the NCAA and is entertaining a scholarship offer from an out of state school.
Kayla Fitts, one of Beggs' opponents during the weekend tournament, told the News she didn't think wrestling Beggs was fair.
A senior at Euless Trinity High School near Dallas, Beggs anticipates competing against boys when she goes to college in the fall.