ISTANBUL -- Ryan Lochte broke his second world record in as many days Saturday at the short-course world championships, setting the mark in the semifinals of the 100-meter individual medley.
The American clocked a world record time of 50.71 seconds, breaking the old mark of 50.76 set by Peter Mankoc of Slovenia in 2009.
On Friday, Lochte broke his own world record in the 200-meter individual medley with a time of 1 minute, 49.63 seconds.
Also at the championships Saturday, Ruta Meilutyte of Lithuania won her second gold medal, taking the 100-meter breaststroke -- the same event she won gold in at the London Olympics.
The 15-year-old Meilutyte won in 1 minute, 3:52 seconds, beating the championship record of 1:03.98 set by American Rebecca Soni in Dubai in 2010.
"It didn't go the way I wanted this morning (in the heats), finally I got it right now. That was the main thing," Meilutyte said. "It's the first time I'm actually really happy with my race, with the splits and the process. Even if I came last, I would be as happy as I am now."
Alia Atkinson of Jamaica took the silver medal in 1:03.80. Rikke Pedersen of Denmark was third in 1:04.05.
Another championship record was set by Brazil's Nicholas Santos, who won the 50 butterfly in 22.22. Chad Le Clos of South Africa got the silver in 22.26, and American Thomas Shields finished third in 22.46.
Robert Hurley of Australia won the 50 backstroke in 23.04, even though Stanislav Donets of Russia was a heavy favorite after clocking the fastest time in the semifinals. American Matt Grevers came in second in 23.17, and Donets won bronze in 23.19.
Donets said he had trouble with his left shoulder this summer and only started training again two months ago.
In Saturday's last finals, the United States won the women's 4x100 freestyle relay when the quartet of Megan Romano, Jessica Hardy, Lia Neal and Allison Schmitt finished in 3:31.01, followed by Australia and Denmark. Shiwen Ye of China powered to the 200 individual medley title with a championship record of 2:04.64, ahead of Katinka Hosszu of Hungary and Hannah Miley of Britain.
Information from The Associated Press was used in this report.