China had won every Olympic title in the sport since a men's singles triumph for South Korean Ryu Seung-min in the 2004 Athens Games, but Xu Xin and Liu Shiwen blew a two-game lead in a thrilling final in Tokyo.

Mizutani and Ito raced into an 8-0 advantage in the deciding game and closed it out when Xu hit a return into the net, with the Japanese pair winning 5-11, 7-11, 11-8, 11-9, 11-9, 6-11, 11-6.

Liu and Xu, the reigning world champions, looked shocked by their defeat as their opponents embraced and celebrated a famous triumph.

The victory also sent the host nation to the top of the overall Olympics medals table at the end of the day's action with eight golds, one more than the United States.

Before this, China had won a remarkable 28 of 32 golds in Olympic table tennis history and were heavily tipped for another clean sweep in the Japanese capital.

"We had been defeated so many times by China at the Olympics and world championships, but we gained revenge at the Tokyo Olympics, I'm so happy," said Mizutani.

Second seeds Mizutani and Ito had been on the brink of a quarter-final exit on Sunday against German duo Patrick Franziska and Petrissa Solja, but saved seven match points to win 16-14 in a seventh game.

This was the first time the mixed doubles event had been played at the Olympics.

Ito, 20, said: "I'm so happy. I was able to do it to the end without giving up. I enjoyed myself throughout the match."

Cheng I-ching and Lin Yun-ju secured bronze for Taiwan with an 11-8, 11-7, 11-8, 11-5 win over French pair Emmanuel Lebesson and Yuan Jia Nan.