BEIJING (AP) Vasyl Lomachenko, a Ukrainian featherweight and the Olympics' most entertaining fighter, overwhelmed another opponent to move one bout away from a gold medal Friday.
Cuba and Russia split two bouts in the long-standing rivalry between the sport's top two powers, with Cuban flyweight Andris Laffita and Russian heavyweight Rakhim Chakhkiev advancing.
After the bouts, Rudi Obreja, a Romanian technical delegate from the International Boxing Association (AIBA), complained about the Olympic refereeing selection process and the sport's judging system.
AIBA disciplinary chief Tom Virgets said the organization is looking into Obreja's list of allegations.
"We have no reason to doubt the integrity of the judges," Virgets said. "But we have a process that we'll follow, because we take any notion of impropriety very seriously."
The afternoon's most memorable display came from Alexis Vastine, the French light welterweight who lost 12-10 to Felix Diaz of the Dominican Republic. Vastine's 9-6 lead had vanished into a 10-all tie when referee Rogelio Fortaleza of the Philippines hit Vastine with a two-point penalty for holding with just 19 seconds left.
Vastine screamed when Fortaleza called the penalty, and he collapsed into waves of tears and wailing after the buzzer. He stepped out of the ring and stretched out on his back on the floor before his equally infuriated coach led him away.
"We all saw what happened," Vastine said through more tears. "I won this bout, but it was stolen. It was unfair."
The French team said it would protest the result, but didn't do so within the allotted time after the bout.
"The penalty was good, and they should have called it earlier," Diaz said. "He was holding all day."
Diaz will face Manus Boonjumnong of Thailand in light welterweight. The Athens gold medalist frustrated Roniel Iglesias of Cuba in a fight that left both boxers complaining of foul play.
Boonjumnong, whose herky-jerky style is as hard to replicate as it is to counter, raised his arms in celebration after just two rounds. Midway through the third round, the Cuban bent his knees and then practically jumped for the ceiling during a third-round clinch, head-butting Boonjumnong with the top of his skull and earning a two-point penalty.
"The head butt was very bad," Boonjumnong said. "It is not fair play, not the sporting thing to do. I could have been hurt and it could have been the end of the fight. ... That is not the way I want to win my fights."
Lomachenko already has beaten his division's top two favorites and the Chinese featherweight. The smooth slugger brutalized Turkey's Yakup Kilic 10-1 - a score that could have been three times as bad if Lomachenko wished.
Lomachenko's final obstacle is Khedafi Djelkhir of France, who beat Azerbaijan's Shahin Imranov.
Laffita won his outstanding bout with Georgy Balakshin of Russia in dramatic fashion, scoring the decisive point in his 9-8 victory on a left hand with about 3 seconds left. Laffita and Balakshin traded impressive combinations throughout the last three rounds.
Chakhkiev won 10-5 over Osmai Acosta, who was unable to win Cuba's fifth consecutive gold medal at heavyweight. Acosta got a two-point penalty for holding in the fourth round, but was always slightly behind Chakhkiev, one of Russia's last two gold-medal hopes.
The middleweight final will feature Cuba's second-generation medal winner, Emilio Correa, against James Degale of Britain, who pounded Ireland's Darren Sutherland 10-3. Correa was nearly as impressive in an 8-5 win over Vijender Kumar, India's first boxing medalist.