Lithuanian teenager Ruta Meilutyte set a world record in the women's 100-meter breaststroke to highlight the second day of the 2013 World Swimming Championships.
Meilutyte, just 16 years old and the gold medal winner at this event in the 2012 London Olympics, had the top semifinal qualifying time Monday, touching the wall in 1 minute, 4.35 seconds. It was 1/10th of a second faster than the previous mark set by American Jessica Hardy in 2009.
Hardy was among the qualifiers Monday. The final will be Tuesday.
Australia's Christian Sprenger won the first gold on Monday, capturing the men's 100-meter breaststroke in a time of 58.79 seconds. He won silver at last year's Olympics, behind South Africa's Cameron van der Burgh, who finished .18 seconds behind on Monday for the silver medal.
Sweden's Sarah Sjostrom claimed gold in the women's 100-meter butterfly with a time of 56.53 seconds. Australia's Alicia Coutts was second, followed by American Dana Vollmer, who set a world record at the distance last year by winning Olympic gold.
Brazil's Cesar Cielo edged American Eugene Godsoe by .04 seconds for gold in the men's 50-meter butterfly, while Hungary's Katinka Hosszu won the women's 200-meter individual medley. She led from start to finish and touched in a time of 2 minutes, 7.92 seconds, beating Coutts by 1.47 seconds.
American Missy Franklin was the top qualifier in the semifinals of the women's 100-meter backstroke, an event she won at last year's Olympics, while American Ryan Lochte had the second-best time in the semifinals of the men's 200-meter freestyle.
Both of those finals are set for Tuesday.