Mack Beggs, 18, a senior from Euless Trinity High School near Dallas, entered the tournament in Cypress outside of Houston with an undefeated record. He beat Chelsea Sanchez -- whom he beat for the title in 2017 -- in the final match Saturday.
"It definitely felt different," Beggs said, according to the Dallas Morning News. "I felt a lot more humble. This year I wanted to prove a point that anyone can do anything. Even though I was put in this position, even though I didn't want to be put in this position, even though I wanted to wrestle the guys, I still had to wrestle the girls."
Video posted online showed a mix of cheers and boos from the crowd after Beggs' win.
Beggs is in the process of transitioning from female to male and taking a low dose of testosterone.
It was his steroid-therapy treatments while wrestling girls that stirred a fierce debate about competitive fairness and transgender rights last season. It has been a lot quieter since last year, when his march to a state championship was dogged by a last-minute lawsuit that tried to stop him.
Beggs had asked to wrestle in the boys' division, but the rules for Texas public high schools require athletes to compete under the gender on their birth certificate.
He entered the state tournament with a 32-0 record, beating three female wrestlers on his way to the championship.
"He has so much respect for all the girls he wrestles," said Beggs' mother, Angela McNew. "People think Mack has been beating up on girls. ... The girls he wrestles with, they are tough. It has more to do with skill and discipline than strength."
McNew would not make Beggs available for interviews ahead of the state meet.?
Kayla Fitts, who lost to Beggs in the semifinals, told the Morning News she did not believe that having to wrestle Beggs was fair.
"The strength definitely was the difference," Fitts said. "I didn't anticipate how strong he was."
Beggs' road to the championship last season included two forfeits in the regional tournament by wrestlers who feared injury. Beggs faced only one forfeit this season. The opposing coach and teammates had insisted the girl wrestle Beggs, but she refused, McNew said.
His family has repeatedly said he wants to wrestle boys. The birth certificate rule was approved in 2016 by the University Interscholastic League, the governing body for Texas high school sports. It was done to help schools determine competition, said Jamie Harrison, the UIL's deputy director.
"I can tell the state Legislature to change the policy, but I can't tell them to change it right now," Beggs said. "All I can hope for is that they come to their [senses] and realize this is stupid and we should change the policies to conform to other people in my position."
Beggs has gone 132-9 over the past three years, including two straight undefeated seasons. He said he has an academic scholarship offer from a small college, where he was promised a spot on the men's wrestling team.
The Associated Press contributed to this report.