Natasha Hastings celebrated an early birthday present by maintaining the United States 100 percent gold medal winning streak in this event as she narrowly outfought the opposition in a tight final to win in 53.41.
Hastings, who celebrates her 17th birthday in nine days time, was well clear at halfway but in the third 100m sector of the race her lead diminished and with 80m remaining Australia’s 15-year-old Jamiee-Lee Hoebergen led by a half-a-metre.
But Hastings caught a second wind and with superior stamina fought back past the tiring Australian.
Russia’s Antonina Krivoshapka came strong on Hastings inside but the American hung on to win in 53.41. Krivoshapka ran a personal best for silver in 53.54 and Hoebergan was rewarded for her bravery with a lifetime best of 53.78.
They were also personal best times for Gemma Nicol of Great Britain (54.16) for fourth and Muna Jabir Adam of Sudan (54.28) for sixth.
