Vladimir Morozov and Katinka Hosszú each grabbed two gold medals on the second day of the International Swimming Federation Swimming World Cup in Jinan in China.
Both swimmers led the World Cup rankings at the end of the first leg of the series in Tokyo and continued to impress at the Natatorium of the Jinan Olympic Sport Centre.
Morozov followed up yesterday's 50 metres freestyle gold by setting a World Cup record to win the 100m freestyle final before claiming the 50m backstroke gold with a World Cup record-equalling 24.42sec.
The Russian clocked 47.99 to top the men's 100m freestyle podium, with American Blake Pieroni second in 48.15.
Szebasztián Szabó of Hungary claimed bronze in 48.63.
Morozov equalled the 50m backstroke record for a third gold medal in two days as he pushed Michael Price of the United States into second.
Price touched the wall in 24.85 for second place as Chinese Jiayu Xu took bronze in 25.25.
Three-time Olympic champion Hosszú secured double gold by winning the women's 100m backstroke and 400m medley races.
In the 100m backstroke, the Hungarian edged out Australian Emily Seebohm by just 0.11 to clinch gold in 59.65.
Seebohm, third in the women's rankings after the Tokyo leg of the World Cup, clocked 59.76 as Jie Chen of China finished third in 1min 00.74sec.
Hosszú stormed to a time of 4:36.99 in the 400m medley, finishing eight seconds clear of compatriot Zsuzsanna Jakabos in a Hungarian one-two.
Jakabos clocked 4:45.28 for silver, while Xin Liu of China rounded out the top three in 4:49.72.
Australian Cate Campbell won the 50m butterfly in 25.63 as compatriot Mitch Larkin claimed gold in the men's 200m medley.
Campbell held off team mate Holly Barratt by a mere 0.03 to claim gold as Jeanett Ottesen of Denmark grabbed bronze in 25.86.
Larkin edged out China's Haiyang Qin to clinch the 200m medley honours in 1:57.26.
Qin was just 0.08 behind, with Thomas Fraser-Holmes sealing an Australian sweep in 2:00.29.
The second leg of the World Cup series concludes in Jinan tomorrow.