Nikolaos Siranidis and Thomas Bimis took the springboard title with a score of 353.34 to the delight of the home crowd, who clapped and cheered as the pair danced around the pool to traditional Greek music played over the public address system.
Chinese divers looked set to make it four golds out of four as Bo Peng and Kenan Wang led the field going into the final round of the three-metre event.
But the duo made a hash of their final dive and the judges declared a no-dive, awarding no points.
American duo Justin and Troy Dumais, second after the penultimate fourth round, also failed to shine and the Greeks pulled off an excellent dive to move ahead of Australians Robert Newberry and Steven
A good final effort from Andreas Wels and Tobias Schellenberg of Germany gave them the silver.
The host nation's win was particularly welcome news for Greeks depressed by a protracted scandal surrounding their top two sprinters who missed doping tests.
"The crowd helped. That was our 'doping'," Siranidis said. "I hope the stadium is always full now when there are diving events."
Bimis said it was time to let the inquiry into the sprinters take its course and concentrate on events in the sports arena.
"I'd like to remind you that the Olympic Games is not only about athletics and football. There are about 30 sports," he told reporters.
"We do our bit and I hope that in this way we are going to open the way for more medals for Greeks."
Adding to a remarkable final, a man dressed in a blue tutu breached security between dives and jumped into the pool in what appeared to be a publicity stunt.
The Chinese win in the women's 10-metre event with a score of 352.14 added to the gold medals the country won in the women's synchronised three metre springboard and men's synchronised 10 metre platform events on Saturday.