Jana Pittman made a late burst to surge past favourite Yulirya Pechonkina and claim gold in the 400m hurdles at the World Championships.
The 20-year-old Australian timed her race perfectly, powering towards the line in a personal best time of 53.22 seconds.
American Sandra Glover was also back to her best form as she edged over the line to snatch silver.
Pechonkina, who had smashed the world record earlier this month, tied up at the line and had to settle for bronze.
The Russian recovered from a stumble at the first hurdle and appeared to be in control of the race but after the ninth hurdle she faded badly.
Pittman grabbed her chance to overhaul Pechonkina and now adds world gold to her Commonwealth crown which she picked up in Manchester last year.
1. Jana Pittman (Aus) 53.22secs
2. Sandra Glover (USA) 53.65
3. Yuliya Pechonkina (Rus) 53.71
4. Ionela Tirlea (Rom) 54.41
5. Tetiana Tereschuk-Antipova (Ukr) 54.61
6. Andrea Blackett (Bar) 54.79
7. Heike Meissner (Ger) 55.60
8. Surita Febbraio (Rsa) 55.90