Keri-Anne Payne admitted she felt under pressure before claiming Britain's second gold of the World Aquatic Championships with victory in the 10-kilometre open water race in Rome.

Payne won a silver at the Beijing Olympics and there were high hopes she could add to the gold won by 15-year-old diver Tom Daley last night. The 21-year-old delivered as she controlled the race to triumph in two hours one minute and 37 seconds.

Payne said: "It feels amazing. I was anxious this morning. There was lots of pressure from the Games, winning a medal. And also I know my funding depends on it."

Today's race had been billed as a fight between the Stockport swimmer and Beijing champion Larisa Ilchenko but the Russian pulled out halfway with a leg injury. Payne then held off Italian Martina Grimaldi on the final circuit before surging off the final buoy to finish more than a body length ahead of Russia's Ekaterina Seliverstova.

The Briton had been determined to go out in front and avoid the pack which sees swimmers involved in a physical battle.

She said: "My plan was just to get out in front and get out of the fight. You can waste so much energy. A few girls wanted to be there but I wasn't having any of it."

Payne will also race in the individual medley over both 200m and 400m.

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

He was third going into the final round but a superbly executed reverse three-and-a-half somersault tuck earned him four 10s from the judges and elevated him into first.

Daley 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, who was the youngest member of Britain's team at last year's Olympics, said: "When I realised I won gold medal I just fell to the floor, I really didn't know what to do. It's amazing. I never thought I would become world champion today."

Spain rocked their way to a gold in the team free combination synchronised swimming event as they performed to Stairway To Heaven.

The routine, which featured air guitar playing as the Led Zeppelin classic reached its crescendo, propelled them to victory with a score of 98.333.