World champion Evgeny Tishchenko won Olympic heavyweight gold at the expense of Vassiliy Levit and Katie Taylor suffered a shock quarter-final defeat in Rio on Monday.
Russian Tishchenko took the title in the 91kg division after he was given a unanimous decision 29-28 29-28 29-28 by the judges in the main event at Riocentro Pavilion 6 on day 10.
There appeared to be little to choose between the two, but all three judges scored the contest in favour of 25-year-old Tishchenko.
The majority of a lively crowd voiced their disapproval when Tishchenko's arm was raised aloft after what was the final bout of the night.
Ireland's defending women's lightweight champion Katie Taylor had earlier been sensationally dethroned, losing on a split decision to Finland's Mira Potkonen.
World middleweight champion Arlen Lopez of Cuba made it through to semi-finals after he was given a unanimous decision in his fight with Frenchman Christian Mbilli.
Potkonen had never beaten Taylor, so there were few who would have given the 35-year-old Finn much chance of winning the opening bout of the day.
The underdog chose a great time to finally get the better of Taylor, going toe to toe with the champion and Ecuadorean judge Clemente Carrillo made the decision to award her the fight after initially scoring it 38-38.
Judge Mykol Karakulov had awarded Taylor three of the four rounds, while Vuong Trong Nghia deemed Potkonen to have had the better of the last three rounds as Taylor fell at the first hurdle.
QUOTES OF THE DAY
"I'm really upset about the reaction of the spectators. I gave everything I had in all my bouts to earn the gold medal. I was whistled after the gong and I don't know the reason for that. But if people behave like this, then they have a reason to be like that. So maybe it was not really fair." - Tishchenko was not impressed with the crowd's reaction to his victory.
"It's very hard to talk about it. Congratulations to her but I should really be beating those girls," - Taylor was shellshocked after her quest for more Olympic glory came to a premature end.
"I have lost so many times to her, so it's great. I was not confident. I am always scared while waiting," - Potkonen expresses her relief after dumping out Taylor.
"I respect the decision of the judges even though I thought I won the fight. It was the judges' decision, I just respected it. It's life, I lost," - Mbilli took his defeat to Lopez on the chin.
Julio Cesar La Cruz and Mathieu Bauderlique enter the ring for the men's light heavy (81kg) final before Brazil's Robson Conceicao will attempt to raise the roof by beating Sofiane Oumiha in the men's light (60kg) gold medal showdown.