Daisuke Takahashi and Mao Asada were the first two skaters to sweep both singles titles for Japan, doing so at the 2010 world championships.
Sui and Han skated to “Bridge Over Troubled Water” and opened with a quadruple twist that may have proved decisive in the end.
“We want everybody to see the splendor, the beauty of figure skating, and also to show the style of Chinese skaters,” Sui said.
Both champions won by wide margins over the second-place finishers.
American Vincent Zhou and Japanese teenager Mana Kawabe are both in second place heading into the free skate.
“Everything is improving now and technically spiritual,” Uno said. “The most important thing I have practiced is the quadruple salchow.”
Though Chen won again this night, the margin was considerably closer. The pair were separated by just two points after the short program.