Russian Evgeny Tishchenko held off Kazakhstan fighter Vassiliy Levit by unanimous decision and won the heavyweight gold medal.
Levit seemed to have the fight won. He battered Tishchenko in the head, causing a cut and caused a lengthy stoppage in the third round. These are the first Olympics since 1980 where the fighters do not wear headgear.
But the judges thought Tischchenko did enough to survive and win the bout. Tishchenko won 29-28 on all three scorecards.
Levit seemed to control most of the fight and the decision was soundly booed by the fans. Tishchenko was booed out of the ring as the medal stand was assembled. Levit simply smirked and shook his head as he headed to the locker room.
The 25-year-old Tishchenko joins an elite lineage of Olympic champions at the glamour weight, including George Foreman, Ray Mercer and three-time Cuban champs Felix Savon and Teofilo Stevenson. Levit beat Savon's nephew, Erislandy, to reach the final.
Savon, a Cuban fighter, and Uzbekistan's Rustam Tulaganov are the bronze medalists.
Two more Americans were out of the Olympic boxing tournament Monday, dropping Team USA to 10-5 in the competition.
Flyweight Antonio Vargas put on a solid performance and took away a lesson for the future in losing on his 20th birthday, dropping a unanimous decision in a preliminary bout to Uzbekistan's Shakhoibidin Zoirov.
Vargas accepted the decision with grace, even after putting on a strong third round against his older opponent. The prospect from Kissimmee, Florida, felt he could have changed things in a fight lasting longer than three rounds.
"I learned a lot of things here, and they're going to make me a better boxer going forward," Vargas said.
Lightweight Mikaela Mayer dropped her bout with Russian Anastasiia Beliakova later Monday in a majority decision in their quarterfinal match.
Though she found it late in life, the 26-year-old Mayer had used boxing to help turn her life around, and her medal quest will have to wait another four years.
One other female American boxer in Rio is still alive. Middleweight Claressa Shields finally begins her gold-medal defense Wednesday.
The six U.S. men in Rio dropped to 9-4 at the Olympics with one bronze medal and two boxers still scheduled to fight for medals this week. That's a marked improvement on the nine-man London team, which won only five fights and failed to bring home a medal.
The men's boxing delegation is the smallest at a non-boycotted Olympics since 1908.