Femke Bol (24) of the Netherlands shattered her own indoor 400-metre world record at the world championships on Saturday.
Bol clocked 49.17 seconds, lowering the previous mark of 49.24 she set two weeks ago at the Dutch national championships, for the first world record of the three-day event at Emirates Arena.
Bol captured gold in the 400m hurdles and 4x400m relay at the outdoor world championships last year in Budapest.
Dutch teammate Lieke Klaver took the silver on Saturday in 50.16, while American Alexis Holmes ran 50.24 for bronze.