Daley stunned by success

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.

Daley was clearly stunned by his achievement and said: "When I was stood up on the board I thought I am going to be happy with a fourth place. Then when it came to the gold medal I just fell to the floor, I really didn't know what to do."

Following his dive he was 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 in Qiu's case fluffed his entry - and the title belonged to the Briton.

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

He added: "I don't know what to say. I don't believe it, I just don't believe it. It's amazing. It was never the day when I thought I would become world champion. I woke up and thought 'just go out and enjoy it and do your best'.

"To come away with a gold medal was unthinkable. It still hasn't sunk in. It makes all the sacrifices worthwhile. Now I want to do it again in 2012."

Daley's dives have a lower tariff - degree of difficulty - than his rivals which meant he was relying on them to make mistakes even if he dived perfectly.

After ending the opening round in first place, he then dropped to fourth for the next three rounds as his lower degree of difficulty counted against him with Zhou pulling away in third.

At this point Qiu was having a private duel with Mitcham for first, but Zhou then had a poor entry on his penultimate dive to offer a glimmer of hope to the Briton.