Olympic champion Michael Phelps won a thrilling 200m butterfly race to secure his first gold medal of the World Swimming Championships in Shanghai.
Phelps, the defending champion, clocked one minute 53.34 seconds to edge out Japan's Takeshi Matsuda, with China's Wu Peng picking up bronze on Wednesday.
Britain's Jemma Lowe and Ellen Gandy won their respective 200m butterfly semi-finals to make Thursday's final.
"I'm loving the fact we're both in the final," Gandy told BBC Radio 5 live.
Phelps, who won the 200m butterfly gold in 2001, 2003, 2007 and 2009, led after 100m but faced pressure from Matsuda, who touched first at 150m.
But the 14-time Olympic champion found another gear in the final 50m to make up for his defeat in the 200m freestyle final on Tuesday and a disappointing bronze as part of the United States' 4x100m freestyle team.
"The race felt good. I wanted to do what I usually do when I'm in better shape," said Phelps, who had arrived in China on the back of a string of defeats.
"I wanted to step on it from the get-go. I saw the other swimmers at the 150 and I put my hips into it. I know there's a lot more I can do in that race."
Lowe, 21, clocked two minutes 06.30 seconds to make the 200m butterfly final as the fastest qualifier, with Gandy qualifying fourth fastest.
"I'm very happy with that as it was quite comfortable," Lowe told BBC Radio 5 live. "I'll try and get some sleep tonight but I probably won't because I won't be able to stop thinking about the final."
Georgia Davies, 20, missed out on a place in the women's 50m backstroke final by 0.07 seconds after finishing fifth in her semi-final with team-mate Gemma Spofforth coming home seventh.
"I'm really disappointed," Davies told BBC Radio 5 live. "I went quite a bit quicker at the trials in Sheffield so I think maybe I've peaked at the wrong time."
Britain's James Goddard qualified for Thursday's 200m individual medley final alongside Phelps and 200m freestyle world champion Ryan Lochte after finishing fourth in his semi-final.
Italy's Federica Pellegrini retained her women's 200m freestyle title to become the first female swimmer to complete the 200m-400m freestyle double at consecutive World Championships.
Felipe Franca da Silva won the 50m breaststroke world title ahead of Italy's Fabio Scozzoli and defending champion Cameron van der Burgh of South Africa.
And China's Sun Yang won the men's 800m freestyle title with Canada's Ryan Cochrane taking silver and Hungary's Gergo Kis bronze.