Zhang is now guaranteed a silver medal after Glazkov's injury
China have three opportunities to win their first ever boxing gold after two semi-final victories and a bye for super-heavyweight Zhang Zhilei.
Light flyweight Zou Shiming outclassed Ireland's Paddy Barnes 15-0, although Barnes hit out at the judging.
Light-heavyweight Zhang Xiaoping sweated out a narrow win over Yerkebulan Shynaliyev of Kazakhstan.
Zhang also advanced by walkover when Vyacheslav Glazkov of Ukraine dropped out with a sprained elbow.
Chinese fans have expected Zou to win their first boxing gold since he took bronze in 2004.
"This time I am fighting at home," Zou said after his semi-final bout. "I will win. I will get a gold medal."
Russia's 11-man team began the tournament expecting to dominate but just two boxers - lightweight Alexey Tishchenko and heavyweight Rakhim Chakhkiev - will fight for gold medals.
But Cuba exceeded most expectations with eight medals and four semi-final winners.