The Olympic champion had already taken care of his ticket to Japan, but the motivation was clear when he won the final in 57.39 seconds, the fifth fastest ever, with exactly 100 days to go.
The Briton, who set a record of 56.88 at the 2019 World Cup in Gwangju, is the only man to have swum the 100m in under 58 seconds and now has the top 20 fastest times in history.
It was also the 15th time he recorded under 58 a second time.
“I had a lot to do with a kid who moved so I’m happy to come here. I think that consolidated the top 20 of all time,” said Peaty, who became a dad last year.
“The execution was perfect, I’m way ahead of where I should be now,” added the 26-year-old. “So I can bring a lot of self-confidence into the summer, the Olympic Games … and show the world that we are a force to be reckoned with.”
The Brit, who uses the event as training, had already swum a 57.70 in the morning runs.
“It’s like nothing else, it’s unreal,” he said of being a father. “Every day he gets older, every day you get more motivated … it’s great to be a father and hopefully be an inspiration to him when he grows up.”