The 27-year-old German improved Poland's Anita Wlodarczyk's previous best of 78.30 set last year with her third throw.

"The world record did not really come as a surprise. I was extremely relaxed and that is part of the confidence I have at the moment. I know when I have to be relaxed," Heidler told reporters.

Hiedler, who won a gold medal at the 2007 Osaka world championships, had a previous personal best of 77.12 set at the 2009 Berlin world championships where she won the silver.