Thiam pipped Jamaica's Lorraine Fenton to the line by two hundredths of a second in a time of 49.86 seconds with Mexico's Ana Guevara taking third in 49.97.

Race favourite Grit Breuer of Germany looked in contention coming into the final 200m, but she failed to find her famous kick as the leading trio broke away.

Guevara headed the pack down the final 50, before Thiam and Fenton produced a battle royale in one of the most exciting finals of the championships.