Barcelona - Lithuanian teenager Ruta Meilutyte lit up the second day of action at the world swimming championships with the first world record of the week as Brazil, Australia, Hungary and Sweden all struck gold at Barcelona's hilltop Palau Sant Jordi on Monday.
Following up on her Olympic title in London last year, the 16-year-old Meilutyte scorched to a time of one minute 04.35 seconds in the semi-finals of the 100 metres breaststroke, shaving a tenth off the previous record of 1:04.45 set by American Jessica Hardy in 2009.
Cesar Cielo of Brazil claimed a second consecutive 50 metres butterfly title, Australia's Christian Sprenger took gold in the 100 metres breaststroke and there were triumphs for Katinka Hosszu of Hungary in the 200 metres individual medley and Swedish teenager Sarah Sjostrom in the 100 metres butterfly.
Hosszu's race produced the biggest surprise of the day when Olympic champion Ye Shiwen of China failed to defend her title from the 2011 championships in Shanghai and finished outside the medals in fourth.
Meilutyte, who trains in England and is chasing the tiny Baltic nation's first world championship gold, had already gone close to the world record in her heat on Monday morning with a time of 1:04.52.
She then became the first Lithuanian woman to break a swimming world record since the country gained its independence from the Soviet Union more than two decades ago.
Improving on Hardy's time had been "one of her dreams" and was more important than winning Tuesday's final but a gold would nonetheless be the "cherry on the cake", Meilutyte told reporters.
"I'll have a relaxing day tomorrow and save all my energy for the final," she added. "My biggest aim is accomplished now and I'll give it my best shot."
Australia came into the championships hoping to put a woeful performance at the London Olympics behind them and Sprenger gave them just the tonic they were seeking when he came from behind to beat Olympic champion and world record holder Cameron Van Der Burgh of South Africa in the day's opening final.
Van Der Burgh, who was coming back from a knee injury, led at the turn but Sprenger powered through to touch in a time of 58.79 seconds, with the South African just behind in 58.97. Felipe Lima of Brazil took bronze with 59.65.
"I remember getting to that first wall and thinking, man I'm travelling really fast and it's not even hurting at all, so I knew I was on track," Sprenger told reporters.
"I could see Cameron in the corner of my eye and I knew he had gone out fast, but I have a stronger back end so it was my turn to come back," added the 27-year-old, second behind Van Der Burgh in London.
"The first thing I saw was Cameron's block and it had the two lights showing and I thought, oh I think I've got him. And then I turned around and saw 58.7 and it blew my mind."
Victory for Brazilian Cielo, a gold medallist in Shanghai, made him only the second man to win the 50 metres butterfly twice after South African Roland Schoeman.
In a relatively slow race, Cielo touched in 23.01 seconds and was close to tears on the podium as his national anthem boomed out around the arena. American Eugene Godsoe took silver in 23.05 and Fred Bousquet of France was third in 23.11.
"It was a very tense final, everyone was very nervous," Cielo, 26, told reporters.
"I think my finish was the key, I think I just put my hand on the wall and I would say that last 10, even the last five metres that was the main difference for me," he added.
"The final is not the time to swim fast, the final is the time to touch first and I'm not surprised we swam a little slower tonight."
Sjostrom, who won the 100 metres butterfly at the 2009 championships in Rome, reclaimed the title after a fourth-place finish in Shanghai.
The 19-year-old touched in a time of 56.53 seconds, while Australia's Alicia Coutts repeated her silver from 2011 with 56.97. Olympic champion and world record holder Dana Vollmer of the United States was third in 57.24.
Coutts went on to claim another silver in the 200 metres medley which may help make up for the disappointment of surrendering the lead to the United States on the final leg of Sunday's 4x100 freestyle relay.
Hungary's Hosszu, sixth in Shanghai and a bronze medallist in Rome in 2009, led on all four legs and touched in a time of two minutes and 07.92 seconds.
Coutts finished in 2:09.39, repeating her second place from 2011, and Spain's Mireia Belmonte Garcia held off Ye and delighted the home support with bronze in 2:09.45 before dedicating her medal to the victims of last week's train crash in Galicia.