Yarisel Ramirez was the last boxer to make the U.S. Olympic boxing team and the first to compete in Tokyo 2020.
The featherweight also suffered the unfortunate fate of being the first American boxer to exit Olympic competition.
Nikolina Cacic made history for Croatia, entering as the nation's first-ever female boxer and also claiming a win over Ramirez in the Round of 32 in the women's featherweight division.
All five judges scored the contest 29-28 in favor of Cacic.
Ramirez joined the U.S. Olympic boxing squad after receiving a slot on July 10, just two weeks ahead of competition. The Las Vegas-based Cuban featherweight was already in Tokyo in hopes of landing a place on the team and wanted to give herself the best possible chance of being ready to fight.
Cacic proved to be a step ahead in the opening round, taking the fight to Ramirez and outworking the American. All five judges agreed, putting Ramirez in an early hole.
Ramirez adjusted in round two, outworking the Croatian to pull even on all five scorecards. It came at the cost of expending a lot of energy, as fatigue set in for both boxers throughout the third and final round.
The judges went with Cacic's cleaner punching to give Croatia its first-ever Olympic win on the female side of competition. It's yet another historic moment for Cacic, who is already her nation's first female boxer to win a medal in an international tournament following her Silver medal performance in the 2018 World Youth Amateur Championships.
Cacic now advances to the Round of 16. She will face Canada's Caroline Veyre, who received a bye in the opening round of competition.
Ramirez's placement granted the U.S. with the distinction of being the only team to have representatives in all five women's divisions. The 21-year-old was expected to be the least likely to medal given the competitive field at featherweight, though was visibly stunned as Cacic's name was announced as the winner.
Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox