Tom Daley was left stunned as he became Great Britain's first diving world champion with victory in the 10-metre platform in Rome.

The 15-year-old was third going into the final round at the Foro Italico but a superbly executed reverse three-and-a-half somersault tuck earned him four 10s from the judges and elevated him into first place.

He was then forced to watch Olympic champion Matthew Mitcham and Qiu Bo, who beat him to the world junior title last year, but the pair did not match their previous high standards and the title belonged to the Briton.

The Plymouth diver won with 539.85 points, with Qiu second ahead of fellow Chinese Zhou Luxin. Less than 10 points separated the top three as Mitcham dropped to fourth.

Daley said: "When I was stood on the board, I thought I am going to be happy with a fourth place.

"Then for my last dive when I came out of the water and saw the 10s coming up I was going into first place. When I knew I was going to get the bronze medal I was so, so happy.

"When I got the silver medal I was like 'Oh my God'. Unthinkable - you can't imagine how over the moon I was. Then when it came to the gold medal I just fell to the floor, I really didn't know what to do."

Daley, who was the youngest member of Britain's team at last year's Olympics, added: "It's amazing. I never thought I would become world champion today."