Daiya Seto was ecstatic after he won the 200m individual medley to break the United States’ stranglehold that stretched back to 2001 at the World Championships in Gwangju, South Korea.
The Japanese led at the halfway point and retained his lead as the field tried to make inroads to win in 1min 56.14secs.
The 25-year-old added gold to the silver he won in the 200m butterfly and with the 400m individual medley to come.
Seto is the first non-American to win the title in nine attempts and he beamed: “This 200m was so big for me because I prefer the 400 individual medley. This is a great step-up for the 400IM.
“I need to concentrate until the last day (for the 400IM) when I want to get my next medal.
“Now I want to continue (my form) to Tokyo 2020.”
Philip Heintz of Germany was locked out of the medals by one place and Mitch Larkin of Australia was seventh.
Australia’s 4x200m women’s freestyle relay squad fended off a challenge from the United States to set a new world record at the World Championships on Thursday.
It was a duel between the two superpowers from the start but Emma McKeon held off her American rival on the final length to pull ahead and win in 7mins 41.50secs.
That time cut 0.58secs from the previous world record set by China almost exactly 10 years ago.
Franzisca Hentze was a heart-breaking fourth in the 200m butterfly with the German missing out by 0.26secs and Marcelo Chierighini of Brazil was fifth in the men’s 100m freestyle in 47.93.
Sarah Sjostrom heads the women’s 100m freestyle field into the final in 52.43 with Cate Campbell second in 52.71.
The Australian welcomed Sjostrom’s form and presence, saying: “I think excellence is driven by competition. I think if you shy away from competition then you shy away from excellence.
“I really enjoy racing the best people in the world: it wouldn’t be the World Championship final without Sarah (Sjostrom) in it and I am really glad it won’t be a World Championship final without me.”
Ranomi Kromowidjojo was ninth, three places above Charlotte Bonnet.
Ryosuke Irie was eighth into the men’s 200m backstroke final.