Max Litchfield stormed to victory in the 400m IM at the British Swimming Championships to book his place at this summer's Worlds in South Korea.
The Sky Sports Scholar, who missed last year's Commonwealth Games through injury, led from start to finish and won gold in 4 mins 10.94 secs.
It was a time that secured his place on the GB team at the World Championships in Gwangju in July.
"I am just thrilled to dip under the qualifying time and book my ticket to Korea for the summer," said the Sheffield swimmer whose brother Joe finish fourth eight seconds behind.
"I've had an awesome block of training and it's good to see it paying off. There is still so much to work on too which is so positive moving forward.
"I've got a day off on Friday and then it's onto the 200IM and 200 Freestyle Saturday and Sunday, so I've still got plenty of racing to go. I can't wait to get stuck in."
GB team-mate and fellow Scholar Freya Anderson also started the championships in golden style on Tuesday with victory in the 200m freestyle, edging out Holly Hibbott by one-hundredth of a second.
The Ellesmere College 18-year-old touched home in 1:58.22 having led throughout.
Anderson, who won two relay golds at the Commonwealth Games last year, said: "I think I can go faster than that.
"I'll get back to training and see what time I can put out. But I'm just getting ready to focus on the 100m on Friday."