Keri-Anne Payne has become the first British athlete to qualify for the 2012 Olympic Games in London.
The 23-year-old swimmer won the gold medal in the 10k open water event at the Fina World Championships in Shanghai to seal her spot.
The top 10 finishers in the race automatically earned Olympic places.
The 2009 world champion and 2008 Olympic silver medallist completed the course at Jinshan City Beach in two hours, one minute and 58.1 seconds.
Italy's Martina Grimaldi finished second, while Greece's Marianna Lymperta was third.
Payne's team-mate Cassie Patten misses out on a place in the team for London after finishing 21st in a time of 2.02:33.01.
"I gave it my best on the day," said Patten, who was a bronze medallist in the event at the 2008 Games in Beijing. "I can't ask for anything more than that."
It was Great Britain's first medal of the competition in China and Payne can now turn her attention to the pool programme, where she has qualified for the 1500m freestyle and 4x200m relay.
"I couldn't be happier right now and it's great to make the team but I know I have to keep going as next year is going to be even harder," said Payne.
"It's an amazing feeling. There is a massive sense of relief because now I can just concentrate on training to make sure I'm at my absolute peak in London."
The Stockport swimmer led from the start of the race in scorching conditions, although Australia's Melissa Gorman and Grimaldi never allowed Payne to get out of sight.
Grimaldi, the 2010 World Open Water Championships winner, and Gorman closed down the Briton as they entered the final stretch, moving to within a body length before Payne responded.
As the front two swimmers surged clear, Gorman dropped off the pace dramatically in the closing stages and was overtaken by the fast-finishing Lymperta.
In a message on her website, Payne added that the event had unfolded as she had expected.
"The race went really well, just how I had planned it," wrote Payne, who also won a bronze medal in the 400m individual medley at the 2010 Commonwealth Games in India.
"I went out from the start and made sure I had enough energy left in the tank to do a sprint finish and cover any moves from the other girls."
Payne, born in South Africa, said her day had been made even better by the news that her sister, Janine, had gone into labour. The swimmer tweeted later that her sister had given birth to a girl.
The final squad for the 2012 Games still needs to be ratified by British swimming and the British Olympic Association but, subject to fitness and form, Payne will be included.
Payne's qualification for the Olympics earned praise from Team GB chef de mission and BOA chief executive Andy Hunt.
He stated: "Keri-Anne's outstanding performance to win gold is a terrific personal accomplishment and the Olympic qualification represents a significant milestone on the road to 2012 for Team GB.
"In terms of Team GB Olympic qualification, that's one down, around 549 to go - well done Keri-Anne Payne for getting the ball rolling."
Payne added: "Last year wasn't the best for me so this is a massive positive and I've also just found out my sister [Janine] is in labour back in the UK so hopefully it will be a good day all round."