Kosuke Hagino won two gold medals in less than an hour as Japan continued to dominate the swimming events at the Asian Games.
For the second day in a row, Japan swept the three men's events while Kanako Watanabe broke China's stranglehold in the women's races by taking out the 200 metres breaststroke.
China, led by their promising teenager Shen Duo, did win two golds to lift their tally to five after two days. Japan leads the medals table with seven while no other country has won at the Munhak Aquatics Center yet.
Hagino took his personal haul to three golds when he followed up his stunning win in Sunday's 200 metres freestyle final by taking out the 200 metres individual medley then joining forces with Yuki Kobori, Daiya Seto and Takeshi Matsuda to win the men's 4x200m freestyle relay.
Junya Koga of Japan won the men's 50m backstroke gold medal for the third Asian Games in a row, while 17-year-old Watanabe beat teammate Rie Kaneto by a tenth of a second in the 200m breaststroke final.
Shen collected her second gold medal of the Games when she won the women's 100m freestyle - one of the sport's blue riband events.
China also won gold in the women's 50m butterfly when Lu Ying got her hands in the wall just before Singapore's Tao Li, who was gunning for her third straight title in the non-Olympic sprint event.