Sleepless Efimova enjoys dream swim, Campbell impresses

Yuliya Efimova of Russia set a world record in the 50 metres breaststroke and Australia's Cate Campbell left her rivals for 50 freestyle gold trailing in qualifying at the world championships in Barcelona on Saturday.

Efimova, who said she had barely slept after Friday's gold in the 200 breaststroke and was stunned by her performance, touched in a time of 29.78 seconds to beat the previous best of 29.80 set by American Jessica Hardy in 2009.

Hardy was swimming alongside the Russian and posted the second-quickest qualifying time of 29.99 seconds. "I still don't understand it," Efimova told reporters.

"Yesterday I was ready for a world record but today, I didn't sleep half the night and I am so tired," the 21-year-old added.

"I didn't do the warm-up and I am so sleepy and I just swam a record it's crazy."

Campbell, whose bid for Olympic gold in the freestyle sprints was wrecked by illness in London last year, posted 24.27 seconds in the 50 metres version on Saturday, well ahead of Briton Francesca Halsall in second with 24.60.

Campbell's younger sister Bronte was third quickest in 24.65 ahead of Ranomi Kromowidjojo of the Netherlands, Olympic champion at 50 and 100 metres, in 24.68.

Campbell put some of the disappointment of missing out at the Olympics behind her by winning the 100 gold on Friday and said she was still recovering.

"I'm stinging a little bit I won't deny but did what I needed to do, got through fairly comfortably so hopefully I can just build on that," she told reporters.

"I didn't get that much sleep or probably as much rest as I would have liked so I am really happy with that swim," added the 21-year-old.

"It's a 50, how much energy can you blow? 50's are fun. They don't hurt. It's splash and dash, essentially."

Sun Yang of China, chasing a rare treble of distance freestyle golds and already the winner of titles at 400 and 800 metres in Barcelona, eased through as the fastest man in qualifying for Sunday's 1,500 final.

Sun, who set the world record at the longer distance to win Olympic gold in London, will match a feat achieved previously only by Australian Grant Hackett in 2005 if he wins all three world titles as expected.

Daniel Orzechowski of Brazil topped the heats for the 50 backstroke ahead of Spain's Aschwin Wildeboer and Frenchman Jeremy Stravius.

Lithuanian teenager Ruta Meilutyte claimed her second world record of the week when she beat Russian Yuliya Efimova's previous best in the women's 50 metres breaststroke at the world championships on Saturday.

Meilutyte, who swam faster than anyone before her in the semi-finals of the 100 breaststroke on Monday, clocked a time of 29.48 seconds in her semi-final to beat Efimova's mark of 29.78 set in qualifying earlier on Saturday.

"Two world records is a dream come true," Meilutyte, who took gold in the 100 final on Tuesday, told Spanish television.

"I've been really close to the world record and I really wanted it and I'm really happy," the 16-year-old added.

Efimova was swimming in the next lane to Meilutyte in their semi-final and finished in 29.88. The Russian owned the record for around eight hours.

American teenager Missy Franklin captured a record-equalling fifth gold medal at a single world championships when she won a second consecutive 200 metres backstroke title in Barcelona on Saturday.

The 18-year-old clocked a time of two minutes 04.76 seconds, a championship record, with Australia's Belinda Hocking taking silver in 2:06.66 and Hilary Caldwell of Canada bronze in 2:06.80.

Franklin already had golds this week in 100 backstroke, 200 freestyle and the 4x100 and 4x200 freestyle relays and she came fourth in Friday's 100 freestyle.

Her fifth triumph means she has matched a feat previously achieved only by American Tracy Caulkins in 1978 and Australian Libby Trickett in 2007.

"It's hard to comprehend but I'm so excited because 200 back is my favourite race so it was so fun to get out there," Franklin told Spanish television.

Asked what her limit might be, she added: "I don't know, I don't think I can choose.

"I'm so flattered I had so many opportunities for all these races and it's so exciting to be able to swim so many times here.

"It's an honour and a privilege and I enjoy every single time I get in the water."

Franklin set the world record to win 200 backstroke gold at the London Olympics last year and also claimed the world title in Shanghai two years ago.