Max Litchfield revealed he was left feeling "weird" after winning his first British title and booking his place at the Rio Olympics.
The 21-year-old City of Sheffield swimmer clinched gold in the men's 400m individual medley at the British Swimming Championships in Glasgow - which double as Great Britain's Olympic trials.
In a thrilling race Litchfield recorded a time of 4:12.05, inside the qualifying standard of 04:12.08, and afterwards he said: "I am over the moon. I have dreamed of this day for years and years, I always said when I was younger that I would make that Olympic team and that has become a real experience since then.
"It is a bit weird really but I am really, really happy.
"I have made the team now and, come Rio, if I get the chance to go there then obviously we can look to make the final and then kick on and get a medal.
"There is no reason why I can't. 4:08 won the worlds (World Championships) last year so there is no reason why I can't drop another few seconds."
Jazz Carlin won the women's 800m freestyle gold but failed to dip below the qualifying time for Rio.
The Welsh swimmer touched the wall at 08:27.49 but the Olympic benchmark was set at 08:22.93.
Carlin, who won 200m freestyle gold on Monday and will race again in the 400m later in the week, said: "It is difficult. I want to be at my best and get on that Olympic team.
"It has been a bit of a tussle for a couple of weeks. I have really put a lot of pressure on myself to not miss out on the Olympics, four years ago it was heart-breaking for me.
"It has been tough and I just didn't feel myself, when you are racing tense you start to get a bit heavy."
Duncan Scott shocked himself when he won British gold for the first time in the Men's Open 100m freestyle, breaking a Scottish record he had broken earlier in the qualifiers.
Scott finished ahead of Englishman Ben Proud in the final in a time of 48.66, albeit outside the Olympic qualifying time of 48.16.
"It was a shock to me. But I'm absolutely delighted," the 18-year-old University of Stirling swimmer said.
"It's my first full year at Stirling and it's showing. It's a great facility and a great place to train."
Fran Halsall stormed to the 50m freestyle title in 24.48 but she too was shy of the qualifying time of 24.37 which left her disappointed.
The 26-year-old Loughborough University swimmer told BBC: "Trials are hard for me, it is me against myself.
"I have been doing really well, training has been going well and to come here and to come here and only swim that time is quite disappointing."
Aimee Wilmott, the 23-year-old from Middlesbrough who competed at the 2012 Olympics, won the Women's Open 200m butterfly with a time of 2:08.82, which was out with the Rio qualifying time of 02.06.51.