Cuba's Osleidys Menendez set a new Olympic record of 71.53m to win gold in the women's javelin.
Czech Nicola Brejchova took the silver with 64.23m, while a throw of 63.61m gave Greece's Mirela Manjani bronze.
Menendez, the world record holder, was head and shoulders better than the opposition, having made the new mark with her opening throw.
The 2001 world champion and Sydney bronze medallist has thrown two metres more than any other woman this year.
Menendez was delighted after picking up her first Olympic gold.
"My first throw was just great, it relaxed me a lot," she said.
"I do not know what comes next, I have already won everything there is.
"I've had a great time here in Greece, I would like to thank my friends and family and all of Cuba who supported me."
In qualification, Britain's Goldie Sayers finished ninth in her pool with a commendable throw of 59.11m, just shy of her personal best.