London, England (Sports Network) - Great Britain's Anthony Ogogo scored a big upset Thursday, when he took out Ukraine's Ievgen Khytrov, the top seed in the middleweight draw.
Khytrov is the reigning world champion, but Ogogo fought him to a draw on points. He won on a judge's decision following a countback.
"I will sleep like a baby tonight," Ogogo said.
Through to the quarterfinals, he will next fight German Stefan Hartel on Monday.
In other middleweight action Thursday, second-seeded Ryota Murata of Japan and No. 4 seed Esquiva Falcao Florentino of Brazil advanced. Romanian Bogdan Juratoni, the third seed, lost.
Ukrainian Vasyl Lomachenko, the featherweight gold medalist in 2008, moved on to the quarterfinals of the lightweight competition. He routed Colombian Eduar Marriaga Campo by a 15-3 margin.
Two Americans, middleweight Terrell Gausha and lightweight Jose Ramirez, both lost.
08/02 18:16:41 ET