Her time beat the previous record held by Libby Trickett set in Melbourne two years ago by .49 seconds.

The Handen-born swimmer first made international waves last year when she won the same event in the European long course championships in a time of 58.44.

In the women's 200m individual medley Hungarian Katinka Hosszu broke the championship record held by American Katie Hoff, when she won in a time of 2:09.12, taking just over a second off the previous best mark of 2:10.13.

Hosszu's record was broken shortly afterwards by American Ariana Kukors, who managed a 2:08.53, just eight hundredth off Stephanie Rice's world record.

The final of the men's and women's 400m freestyle, as well as the men's and women's 4x100m freestyle relay will be held later Sunday.