Britain's Ellen Gandy won silver in the 200m butterfly at the World Swimming Championships in Shanghai.
Gandy, 19, came on strong down the final length but China's Jiao Liuyang clocked two minutes 05.55 seconds to pip her by 0.04 seconds.
Gandy's fellow Briton Jemma Lowe, who qualified fastest for the final, finished a disappointing seventh.
Ryan Lochte broke his own world record to beat Michael Phelps and win the 200m individual medley gold.
Gandy's medal is only Britain's second in the pool - Rebecca Adlington won silver in the 400m freestyle, while Kerri-Anne Payne won gold in the 10km open water.
Olympic, defending world champion and world record holder Liu Zige was third in a time of 2:05.90.
Lochte, who also overcame Phelps in the 200m freestyle final, touched home in 1:54.00 seconds to edge out his fellow American by 0.16.
It was the first world record to be set since the controversial high-tech body suits were banned at the start of 2010.
Britain's James Goddard, who has been battling a shoulder injury, was fourth.
Phelps, the 14-time Olympic champion, was seeking to add to the 200m butterfly title he won on Wednesday, and led for the opening butterfly leg.
But Lochte surged into the lead during the second length before powering home in the freestyle.
The victory was a huge confidence boost for Lochte with the London Olympics now less than one year away. The 26-year-old won the silver behind Phelps in the same event at the last two Games in Athens and Beijing.
Lochte said: "Any time you break the world record you've got to be excited. I trained hard and it paid off. I knew this was going to be a battle between me and Michael and I got the better end this time."
Phelps said Lochte's performance demonstrated that records could fall despite the end of the 'super-suits' era that saw 43 world marks shattered at the Rome World Championships in 2009.
"It says a lot we're still able to do those times," said Phelps, winner of 16 Olympic medals. "It's not impossible for us to see world records right now, I think we're going to start seeing more."
Goddard, who was close to tears, said: "I'm really disappointed. It was anyone's game for the bronze medal. The semi-finals kind of showed it was up for grabs and I'm pretty gutted I missed it."
Australia's James Magnussen won the men's 100m freestyle, clocking 47.63 to finish ahead of Canada's Brent Hayden and William Meynard of France, with Brazilian defending champion Cesar Cielo fourth.
Fran Halsall was the fastest qualifier for Friday's 100m freestyle final after winning her semi-final in 53.48, but Amy Smith finished last and did not go through.
The 21-year-old Halsall said: "I'm really happy with that. This morning I was a little bit nervous, I hadn't swum since Sunday. On Friday I've got to give a little bit more, a medal would be nice."
Britain's women's 4x200m freestyle relay squad fnished sixth in the final, while Britons Andrew Willis and Michael Jamieson qualified fifth and sixth fastest respectively for the 200m breaststroke final.