World champion Daiya Sato was the only double winner on Saturday as he claimed victories in the men's 200m butterfly in a Japanese national record time of 1:52.53 and the 200m individual medley on 1:55.55.

"I am surprised by my 200m fly because I was not in my best form. But the time boosts my confidence. It is a great start for me," Sato said.

In other women's events, Katinka Hosszu of Hungary snatched the gold in the 200m backstroke, Ajna Kesely of Hungary topped the 400m freestyle in 4:09.10, Siobhan Haughey of Hong Kong, China was the fastest in the 100m freestyle in 53.33, and Molly Hannis of the United States beat Jamaican veteran Alia Atkinson in the 50m breaststroke.