It is the Afghan-born swimmer's first win since being granted American citizenship after settling in the county in 2016.

"It's an honour for me to become an American citizen and winning a gold medal for the first time as a citizen is very exciting," said Karimi.

"I’m very thankful for all the people that have been helping and supporting me.

"It's just unbelievable, I’m still in disbelief after nine-and-a-half years, I finally got my citizenship and I’m just living my dream and so excited for what’s next for me."

Joining Karimi on the podium were compatriots Zach Shattuck and Adin Williams in second and third, respectively.

In the women's 50m butterfly it was two-time Paralympic gold medallist Elizabeth Marks who led another American podium sweep at the Indiana University Natatorium.

Triple Paralympic champion Mallory Weggemann and two-time Tokyo 2020 bronze medallist Julia Gaffney occupied the remaining spots.

One day after breaking two world records, Leanne Smith was back on the podium, grabbing her third gold after a win in the women’s 50m freestyle.

Overall, seven of the eight finals were won by Americans with Chile's Alberto Abarza the only outlier.

Abarza triumphed in the men's 50m freestyle with the US' Jamal Hill in second and Montenegrin Ilija Tadić third.

Lizzie Smith triumphed in the women's 100m butterfly while Lawrence Sapp took the win in the men's equivalent.

Morgan Stickney and Matthew Torres were the respective winners in the women's and men's 400m freestyle.