<p>Australia's Emma McKeon broke the Olympic record in the women's 100m freestyle preliminary heats on Wednesday with a time of 52.13 seconds.</p>.<p>McKeon broke the 52.62 set by Sarah Sjostrom, and the time was also a new personal best for the Australian.</p>.<p>Hong Kong’s Siobhan Haughey, who won silver in the 200m freestyle earlier on Wednesday, was second quickest in 52.70 ahead of Great Britain's Anna Hopkin and Australia's Cate Campbell.</p>.<p>Great Britain's Luke Greenbank was fastest in the men's 200m backstroke heat on 1:54.63 ahead of Russian Evgeny Rylov, one of the favourites for the gold medal.</p>.<p>American Bryce Mefford was third ahead of South Korea's Lee Juho.</p>.<p>The silver medalist in the women's 100m backstroke, Tatjana Schoenmaker, was fastest in the 200m backstroke heat posting a time of 2:19.16, with American Lilly King second quickest.</p>
<p>Australia's Emma McKeon broke the Olympic record in the women's 100m freestyle preliminary heats on Wednesday with a time of 52.13 seconds.</p>.<p>McKeon broke the 52.62 set by Sarah Sjostrom, and the time was also a new personal best for the Australian.</p>.<p>Hong Kong’s Siobhan Haughey, who won silver in the 200m freestyle earlier on Wednesday, was second quickest in 52.70 ahead of Great Britain's Anna Hopkin and Australia's Cate Campbell.</p>.<p>Great Britain's Luke Greenbank was fastest in the men's 200m backstroke heat on 1:54.63 ahead of Russian Evgeny Rylov, one of the favourites for the gold medal.</p>.<p>American Bryce Mefford was third ahead of South Korea's Lee Juho.</p>.<p>The silver medalist in the women's 100m backstroke, Tatjana Schoenmaker, was fastest in the 200m backstroke heat posting a time of 2:19.16, with American Lilly King second quickest.</p>