SWIMMING: There was plenty of excitement at the Aquatic Centre on Thursday morning, with four AYOF records broken in the heats.

The women's 200m freestyle record was broken by Amelia Gould of Australia Green. Her time of 2:00.34 replaced the existing record of 2:00.53, set by Yi Tang of China in 2007.

In the men's 200m freestyle, Regan Leong of Australia Gold touched the wall in a record time of 1:50.76, beating Australian Justin James’ record of 1:51.51 set in 2009. There were some solid performances by Toru Maruyama of Japan, who maintained a strong lead throughout heat three, and Mack Horton (Australia Green), who surged forward in the last 50m to overtake Maruyama and win the heat.

Hayley Baker of Australia Green took more than a second off the record in women's 100m backstroke with her time of 1:01.86, while Canadian Sydney Pickrem was disqualified after an early start.

Takeshi Kawamoto of Japan gave an incredible performance in the men's 100m backstroke, maintaining a strong lead before breaking the record of 56.41, set in 2003 by Matt Grevers of USA, with his time of 55.04. Grevers has since gone on to win gold in the 100m backstroke at the London 2012 Olympics, breaking the world record at the same time.

It was a close finish in the men's 200m butterfly, with Masato Sakai of Japan finishing just a second ahead of teammate Ryo Fujimoto.

Four Australian girls have qualified for the women's 200m butterfly final: Madeleine Groves, Alanna Bowles, Meg Bailey and Megan Gianotti. They will make up half the finalists due to compete again on Thursday night.

With so many close finishes and record breaking times in the heats, the finals are sure to produce more of the same.

Hannah Moore
Olympics.com.au