In terrible conditions for pole vaulting, Russian Yelena Isinbayeva took just one vault at 4.65m to seal the win and make sure she stayed in the race while Jamaican Kerron Stewart posted her fourth consecutive 100m win in 10.99sec.

"The wind was turning round and round," Isinbayeva said. "It was difficult to produce a great performance under those kind of conditions."

On a good night for American athletes, Sanya Richards also ensured she stayed on course for the jackpot with victory in the women's 400m in 49.34sec, more than one gaping second ahead of her rivals. Richards, who lost out on Olympic gold to Britain's Christine Ohuruogu, said: "I'm very satisfied with my victory. It was cold tonight and I am proud I ran under 50sec."