China took advantage of Argentina's frontcourt injuries to post an 87-77 victory that put it in good shape for its first men's quarterfinal berth.
Hu Wei-Dong and Zheng Wu each had 22 points for China (2-1), which has preliminary-round games left against the United States and Lithuania but should still finish fourth in its six-team pool and advance.
China's best previous Olympic finish in five appearances was 10th in 1984. The Chinese finished eighth at the World Championships two years ago.
Argentina (1-2) played without power forward Marcelo Nicola and center Ruben Wolkowisky.
Shane Heal scored 13 of his 35 points in the second overtime, leading Australia to a 109-101 victory over Brazil.
Heal converted a four-point play nine seconds into the second overtime to put Australia (2-1) ahead to stay.
Brazil (1-2) missed six of nine shots in the second overtime. Oscar Schmidt finished with 24 points.
Predrag Danilovic scored 19 points to lead eight players with at least eight points in Yugoslavia's 118-95 rout of South Korea.
Danilovic, who plays for the Miami Heat, had 13 points in the first half as Yugoslavia (3-0) scored at will from inside to take a 57-28 halftime lead.
Joo-Yeop Hyun had 20 points to lead South Korea (0-3), which has only one player taller than 6 feet 5.
Dino Radja had 20 points and Toni Kukoc added 16 as Croatia finally pulled away from Angola (0-3) for a 71-48 victory.
Nikos Economou scored 19 points and Greece held off a furious rally by Puerto Rico for an 80-69 victory.
Greece (2-1) appeared in control when it scored the first eight points of the second half to take a 59-33. But Puerto Rico (1-2) responded with a 20-0 run.