Three world records today at the World Swimming Championships in Budapest.
Britain's Adam Peaty broke the 50m breaststroke world record for the second time in a day as he reached the final.
The defending champion won the semi-final in 25.95 seconds, becoming the first person to break 26 seconds and eclipsing his 26.10 in the heats.
Peaty retained his 100m breaststroke title yesterday.
Lilly King of the United States added the world title to her Olympic crown by powering to the women's 100 metres breaststroke title in world record time.
King posted one minute 4.13 seconds to hold off Russian rival Yuliya Efimova in a grudge rematch of their acrimonious Olympic final and eclipse the world mark set by Lithuania's Ruta Meilutyte in 2013.
King has voiced her disapproval that Efimova is allowed to compete at global level after the Russian has twice been caught using banned substances.
The spiky relationship continued in Budapest as King celebrated her victory wildly and did not exchange eye contact with Efimova who took bronze.
Canada's Kylie Masse set a world record for the women's 100 metres backstroke breaking the previous mark of 58.12 seconds set by Britain's Gemma Spofforth at the 2009 world championships.
New Zealander Corey Main finished 8th in the men's 100 backstroke final.
Bradley Ashby won his heat of the 200 butterfly but his time wasn't quick enough to get him into the semi-finals.