|World Swimming Championships|
|Venue: Kazan, Russia Dates: 2-9 August|
|Coverage: Live on BBC Two, Radio 5 live sports extra, online, tablets, mobiles and BBC Sport app.|
Great Britain's Adam Peaty won 50m breaststroke gold at the World Swimming Championships to become the first man to complete the 50m and 100m double.
The 20-year-old then helped GB win mixed 4x100m medley relay gold in a world record time in Kazan.
Chris Walker-Hebborn, Peaty, Siobhan-Marie O'Connor and Fran Halsall triumphed in three minutes 41.71 seconds for Britain's fourth gold.
"We fought for every inch. We left it all on the battlefield," Peaty said.
Peaty beat South Africa's Cameron van der Burgh into second place in the 50m breaststroke final, in a repeat of Monday's 100m final.
Peaty won in 26.51 seconds, with South Africa's Van der Burgh 0.15secs behind and American Kevin Cordes third.
World record changes hands
Britain became the third country at these championships to set a world record in the mixed 4x100m medley, which is not an Olympic event.
Russia clocked 3:45.87 before the USA recorded 3:42.43.
Russia's time was also bettered by both Germany and the British line-up of Walker-Hebborn, Ross Murdoch, Rachael Kelly and Halsall in the semi-final.
But Britain beat the USA into second and Germany into third as they set a new record in the final.
A total of 10 world records have been set at the championships.
|Britain's World Championship golds|
|Adam Peaty: 100m freestyle||James Guy: 200m freestyle|
|Adam Peaty: 50m freestyle||4x100m mixed medley relay|
What about the other Britons?
Stephen Milne was seventh in the 800m freestyle final but Hannah Miley failed to reach the 200m butterfly final.
Milne, who competes in the 1500m later in the week, clocked seven minutes 49.86 seconds, while Miley was joint 14th fastest of the semi-finalists in 2:09.21.
Lauren Quigley reached Thursday's 50m backstroke final by finishing seventh fastest in 27.88.
Dan Wallace qualified for Thursday's 200m individual medley final with 1:57.77, which was second fastest in his semi-final and fourth fastest overall.
Roberto Pavoni lost a swim-off for the final against American Conor Dwyer after finishing joint eighth fastest in the semi-finals.
Benjamin Proud and Calum Jarvis missed out on the 100m freestyle semi-finals after finishing in 49.35 and 49.68 respectively in the heats.
Meanwhile, Britain's Gary Hunt won gold in the 27m high diving competition.
Best of the rest
American Katie Ledecky, 18, added 200m freestyle gold to her 1500m gold by beating two-time winner Federica Pellegrini and defending champion Missy Franklin in 1:55.16.
Ledecky, who won four golds at the 2013 World Championships in Barcelona, said: "I knew that I could trust in my training. That confidence has fuelled my swims this week."
China's Sun Yang followed up his 400m freestyle gold with victory in the 800m in 7:39.96, ahead of Gregorio Paltrinieri and Mack Horton of Australia.
Laszlo Cseh of Hungary beat defending champion Chad le Clos and Jan Switkowski to win the 200m butterfly in 1:53.48.
|Medal table after day four|