American fencer Stephanie Turner was disqualified from a tournament in Maryland for refusing to compete against a transgender competitor.
Fox News reported that before facing Redmond Sullivan, who had previously competed against men, Turner dropped to one knee and told the referee she refused to fight.
The American player was shown a black card, which means disqualification.
USA Fencing later announced that Turner was disqualified for refusing to compete against a specific opponent who had been entered into the tournament in accordance with all rules.
Earlier, US President Donald Trump signed an executive order banning transgender people, who were assigned male at birth, from participating in women's sports.
US Congresswoman Nancy Mace said the law would restore justice and protect the rights of female athletes.