CHICAGO (AP) — A man looking to steal a cell phone may want to rethink his ability to size up victims after a woman he tried to rob turned to be a boxer who knows punching below the belt may be illegal in the ring but on the street it’s a pretty effective way to stop and opponent.

Twenty-six-year-old Golden Gloves champion Claire Quinn says she was walking Sunday in Chicago’s Bucktown neighborhood when a man sucker punched her from behind and demanded her cell phone.

But Quinn fought back. And even though she was hit hard enough to suffer a concussion, she told the Chicago Tribune that she “kept throwing my right hand into his groin.”

Finally, the man ran off.

Police confirmed the attack but say no arrests have been made.