Australia's Emma Snowsill ran away with the women's Olympic triathlon gold medal, as world champion Helen Tucker trailed in 21st.
Britain's world champion only 21st as Australian powers away to gold.
Australia's Emma Snowsill ran away with the women's Olympic triathlon gold medal, as world champion Helen Tucker could only trail in 21st.
Three-time world champion Snowsill did all the damage in the closing 10km run stage as she reversed the placings with current world number one Vanessa Fernandes of Portugal.
Snowsill was far too strong for her Portuguese rival after an explosive start to the run, and she eventually finished just over a minute ahead in a time of 1 hour 58 minutes 27.66 seconds.
With Fernandes settling for the silver medal, another Australian, Emma Moffett took the bronze as Great Britain's big hope Tucker found the pace too quick as she finished well down the field.
Veteran
Veteran American Laura Bennett led after the 1500m swim ahead of compatriot Sarah Haskins and Switzerland's Magali di Marco, with Tucker in contention in eighth.
After a slow start to the 40km bike ride, Tucker pulled herself back into the leading group, which by now contained Snowsill and Fernandes, but the other British hope Hollie Avil was struggling.
Avil had been suffering with food poisoning and after the 18-year-old slipped well back during the bike ride she was forced to pull out of the race.
New Zealand's Andrea Hewitt exited the final transition in the lead but that did not last as Snowsill came steaming out into the 10km run and soon took up the running.
A powerful start from the Australian gave her some clear distance ahead of Fernandes, who was now pushing hard but was 39 seconds behind halfway through the run, with Tucker well over a minute behind.
Chase
Fernandes moved away from the chasing pack including Bennett, Hewiit and Moffett to start a lone chase for the Australian, but she could not get anywhere near close enough.
In the end the Australian was able to slow down to almost a walk, and pick up her national flag to carry over the line with her at the finish.
"I didn't feel awesome," said the 27-year-old Snowsill. "It was extremely hard, it was hot. I think it was a great course for a triathlon. It was a really tough course.
"I feel very proud and honoured to be an Australian with a gold medal around my neck at the Olympic Games.
"I believe we came so close in Sydney and Athens that this makes up for those very close defeats.
"I don't feel any regret about not going to Athens, you move on and you deal with it. But to come from a nation that's so strong in terms of triathlon, it's a fantastic feeling to finally bring home a gold medal."
