Cannot play media. Sorry, this media is not available in your territory.
Video - Zhang hangs on to her title
Zhang Ning retained her Olympic badminton singles title with a superb fightback to beat fellow Chinese star Xie Xingfang 21-12 10-21 21-18.
Zhang, almost certainly playing her last match at the age of 33, struggled as world number one Xie gained ominous momentum in the second game.
But China's defending champion produced a defiant performance to take the gold.
Earlier, China missed a clean sweep of the medals when Indonesia's Maria Kristin Yulianti took bronze.
"After Athens I didn't think about participating in Beijing," said second seed Zhang following her victory.
I'm 33 years old and I made it to the finals - I believe it was tenacity that got me this gold medal
"I wasn't doing very well, I was kind of confused and I didn't know what to do, but then I persevered. I tried very hard and did a lot of training, so this gold didn't come very easily.
"I'm 33 years old and I made it to the finals - I believe it was tenacity that got me this gold medal."
Zhang's imminent retirement may be followed by Xie's withdrawal from badminton, if speculation in China is to be believed.
The losing finalist admitted she could not envisage an appearance at the London 2012 event in four years' time.
"I'm not thinking about London now, it's hard to imagine I will participate," she told reporters.