Sun Yang was chasing gold again Sunday, leading the way into the men's 200m freestyle semi-finals just one day after he gave China it's first men's Olympic swimming title. In a field packed with talent from around the globe, newly-minted 400m freestyle gold medallist Sun topped the qualifying times in 1min 46.24sec, edging American Ryan Lochte in their heat by 21-hundredths of a second. Lochte, who detroyed a field that included 14-time Olympic gold medallist Michael Phelps to win the 400m medley on Saturday night, said his main aim of the morning was to secure a good lane for his semi-final swim. "It's a new day and new race," Lochte said. "I did what I had to do and hopefully I'll be a lot faster tonight." France's Yannick Agnel, who topped the world rankings coming into the Games, was third-fastest ahead of Russian Danila Izotov and South Korean Park Tae-Hwan -- who took silver behind Sun in the 400m free after a rollercoaster day that saw him disqualified in the heats and then reinstated to the final. © AFP Ryan Lochte reacts after he was edged out of first place by China's Sun Yang at the men's 200m freestyle heats © AFP Fabrice Coffrini World record-holder Paul Biedermann of Germany -- who failed to qualify for the 400m free final -- made it safely into the semis with the 10th-fastest time. Australian Emily Seebohm set the pace in the women's 100m backstroke preliminaries, winning her heat in 58.23sec -- an Olympic record and the third-fastest time in history. "I saw that I was ahead of the world record at the 50 split and I was just like, 'Don't get over your head, just keep going and just go as hard as you can,'" Seebohm said. "All I wanted to do this morning was to make it through," said Seebohm, a medley relay gold medallist in Beijing who won eight medals at the 2010 Commonwealth Games but was hampered by illness in 2011. "My goal was just to keep moving forward and now maybe the world record in the final, who knows?" The top 10 swimmers in a quality field all dipped under the one-minute mark as 16 booked their places in the evening's semi-finals. © AFP Missy Franklin launches herself from the blocks during her 100m backstroke heat on Sunday © AFP Christophe Simon US teenager Missy Franklin was second-quickest in 59.37 ahead of Australian Belinda Hocking (59.61) and Japan's Aya Terakawa (59.82). "It was awesome watching Emily Seebohm break the Olympic record, that was unbelievable," said the ebullient Franklin, who is finding inspiration everywhere she looks at her first Olympics. "She did such a good job, but I am really happy about how I did and I'll be focusing on that tonight." Russia's Anastasia Zueva, owner of the second-fastest time in history, was fifth-fastest in 59.88, while China's Fu Yuanhui and Zhao Jing moved smoothly into the semis with the eighth- and ninth-fastest times. British world record-holder Gemma Spofforth advanced with the 12th-fastest time and Zimbabwe's Kirsty Coventry, silver medallist behind American Natalie Coughlin at the last two Olympics grabbed the penultimate semi-final berth. Heats of the women's 100m breaststroke, men's 100m backstroke, women's 400m freestyle and men's 4x100m freestyle relay were also on tap Sunday morning.