Swain (r) in action during the Beijing Olympics
Teenager Charles Calvert claimed a surprise win in the men's three-metre springboard title at the British Diving Championships in Sheffield on Friday.
The 18-year-old pushed Beijing Olympian Ben Swain, 22, into second, 37.9 points behind the winner.
Displaying superb technique Calvert, who dives for City of Leeds, broke 70 points in all but one of his six dives.
He also gained enough points to go past the 1,200-point qualifying criteria for July's World Championships in Rome.
"I knew it was possible (to reach the qualification criteria) on the last dive, but I just blocked it out and worried about the dive," added Calvert.
"I'm not so much disappointed because I am on a four-year plan
"I was extremely nervous. My hands were shaking and I was going through a few breathing techniques I have been working on with my coach.
"I knew I could do it. The diving board is my house."
British Diving now must decide whether Calvert will go to the World Championships.
"I'll just sit and wait for the call now," said Calvert, who only a year ago finished fourth in this event at the national titles.
"It would be an amazing experience if it does happen."
Competing for the first time since finishing 26th at the Olympics, Swain attempted a new repertoire of more difficult dives in a bid to improve his chances against the world's best.
"I'm not so much disappointed because I am on a four-year plan," said Swain, who on Thursday won the 3m synchro title with Nicholas Robinson-Baker for the second year running.
In the women's 10m platform Sarah Barrow edged out Beijing Olympian Tonia Couch, although both met the qualification criteria for the World Championships.
Tom Daley had been due to make his first competitive appearance on Friday in the 10m synchro platform, but missed out after his partner Blake Aldridge's suffered a broken nose after he was involved in an alleged nightclub fracas in Southampton last Friday.
As a result only Jack Chewlow and Max Brick competed in the 10m synchro platform to claim the national title, while Hayley Sage and Claire Blencowe won the women's 3m synchro springboard.
On Thursday Helen and Carol Galashan took their first gold medal as they stormed to victory in the women's 10m synchro event.
The Galashan twins took the victory from Olympic diving pair Stacie Powell and Tonia Couch after debuting a technically difficult back armstand dive.