LONDON (REUTERS) - American Kori Carter pulled off another shock at the World Athletics Championships on Thursday (Aug 10), achieving the rare feat of winning the 400 metres hurdles title from the outside lane.

All eyes had been on Carter's US team mate, Olympic champion Dalilah Muhammad, who had been the favourite, but it was the former NCAA champion in lane nine who maintained her form best as she raced to victory in 53.07 seconds.

Muhammad, the fastest in the world this year, earned the silver in 53.50 to complete a US one-two while Jamaican Ristananna Tracey, an Olympic finalist last year, took the bronze in 53.74.

Czech Zuzana Hejnova, who had been seeking to achieve an unprecedented third successive one-lap hurdles victory, had to settle for fourth, despite running a season's best of 54.20.