Complete the following sentence: London 2012 middleweight champion Claressa Shields was the U.S. female boxer to upgrade her Olympic spot with a quarterfinal victory at the
World Championships in Astana, Kazakhstan.<unk> Antonio Vargas and Gary Antuanne Russell were the only Americans to secure additional places on the boxing team at the 2016 AIBA World Qualifying Tournament in Baku, Azerbaijan.<unk> Antonio Vargas and Gary Antuanne Russell were the only Americans to secure additional places on the boxing team at the 2016 AIBA World Qualifying Tournament in Baku, Azerbaijan.