Roundup: Sun says 200m freestyle gold the best win of career

China's Sun Yang described his victory in the men's 200m freestyle final at the Rio Olympics on Monday as the best of his career, usurping his 400m and 1500m triumphs at the London 2012 Games.

Sun finished the final in 1 minute 44.65 seconds, 0.55sec ahead of South Africa's Chad le Clos, with the USA's Conor Dwyer 0.58sec further back.

The gold medal, China's first in the pool at the Rio Games, made up for Sun's disappointment at taking silver in the same event at the London 2012 Games.

"This means more than the gold medal from the 400m and 1500m in London," Sun said. "I had already won those events at the world championship, but the 200m freestyle has been elusive until now."

Sun declined to comment on his row with rival Mack Horton, who has described the Chinese swimmer as a "drug cheat". Sun served a three-month ban in 2014 after testing positive to an illegal substance, which he says he unknowingly took as part of treatment for a heart condition.

"I just focus on my own competition and not what other people are saying," Sun said.

"I feel responsible for the success of Chinese and Asian swimming and I want to keep working hard to achieve our goals."

Earlier on Tuesday, US swimmer Lilly King smashed the Olympic record to win the women's 100m breaststroke gold medal.

King, 19, clocked 1 minute 4.93 seconds in the final, beating the previous record of 1:05.39 held by Australian Leisel Jones.

"Tonight has been so crazy. My life is changing right now," King said. "I'm a gold medallist and it's what I've always wanted to be and it's an incredible feeling.

"I'm probably going to start crying. I'm usually not a crier but this is a special moment so we'll see if it gets to me or not."

Russia's Yulia Efimova took silver in 1:05.50 and the USA's Katie Meili bronze in 1:05.69.

World record holder Ruta Meilutyte of Lithuania was seventh, 2.39sec behind King.

US swimmer Ryan Murphy set a new Olympic record to win gold in the men's 100m backstroke.

Murphy posted a time of 51.97sec to eclipse the previous record of 52.16sec set by his countryman Matthew Grevers at the London 2012 Olympics.

"The adrenaline is going so hard for me right now, I don't even feel tired just because I'm so excited," Murphy said. "This means everything to me. I've been swimming for 16 years and to have it come to this is just a dream come true."

China's Xu Jiayu took silver, 0.34sec behind Murphy, and David Plummer pocketed bronze, 0.43sec further back. Plummer is the oldest US Olympic debutant since 2004.

Australia's Mitchell Larkin was fourth in 52.43sec.

Hungary's Katinka Hosszu grabbed her second gold medal of the Rio Olympics by winning the women's 100m backstroke final.

Hosszu clocked 58.45 seconds to finish 0.30sec ahead of Kathleen Baker of the USA and 0.31sec in front of Canada's Kylie Masse and China's Fu Yuanhui, who tied for bronze.

Olympic record holder Emily Seebohm of Australia was seventh, 0.74sec behind Hosszu.

On Sunday Hosszu won the gold medal and broke the world record in the 400m individual medley.

Michael Phelps qualified second fastest for the men's 200m butterfly in 1:54.12, just 0.16sec behind Hungary's Tamas Kenderesi. Laszlo Cseh, also of Hungary, was third, 1.22sec further back.

Sweden's Sarah Sjostrom qualified fastest for Tuesday's women's 200m freestyle final by clocking 1:54.65 in her semifinal. Katie Ledecky of the USA was second quickest in 1:54.81 and Italy's Federica Pellegrini was third in 1:55.42. Endit