China's Sun Yang broke the second world record of the meet Sunday, taking down Aussie Grant Hackett's 10-year-old mark in the 1,500 freestyle.
Sun was more than two seconds off Hackett's pace with four laps to go in swimming's version of the mile, but he accelerated on the final two laps to finish in 14:34.14, improving on Hackett's mark of 14:34.56 set at the 2001 worlds.
"I was not obsessed with the world record before the final, because I wanted to focus on my plan," Sun said. "My goal is to win the gold."
The 19-year-old Chinese also won the 800 free, along with a silver in the 400 and a bronze on China's 4x200 free relay.
"After winning the gold medal, I think more and more people will pay more attention to me," Sun said. "There's no doubt I will feel more pressure, but I'm still young and I don't want to be burdened by gigantic pressures. So next year, I will keep a relaxed mindset so I can handle future races."
Canada's Ryan Cochrane was second in 14:44.46, while Gergo Kis of Hungary finished third in 14:45.66.