The Chinese pulled off a nearly perfect performance to garner 275.997 points, beating Japan's by 4.045 points.

Japan, initially placed in fourth place, picked the silver medal after winning an appeal against the pommel horse score on Kohei Uchimura.

Host gymnasts dropped from second to third for bronze, Britain's first team gymnastics medal for a century.

China made a series of mistakes in the qualifying, but did nothing wrong in the final, which drew media suspicions that the defending champions had hidden their strength.

"There is no hiding at all in the qualification," said Zou Kai, the triple gold medalist in the Beijing Olympics. "Who would like to stay back in the Olympic qualifying? If we do so, we lose chance in individual finals."

Chinese Olympic debutant Zhang Chenglong said he had learned how to deal with stress.

"I did not feel a lot of pressure in the final in spite of our mistakes in the qualifying," he said. "We had beaten Japan before. We are just fighting the old opponents."

China ranked sixth in the qualifying and Japan fifth, making the two arch rivals in the same rotation in the final.

Japan, silver medalists in Beijing, started their challenge from rings, which earned 0.8 points ahead of China.

In the second rotation of vault, China gained their lead once for all as all three gymnasts completed the discipline before Japan.

Japan's Koji Yamamuro banged on his knees and arms on his landing and had to be carried off by team medical staff.

China overtook Japan by 1.542 points after the vault rotation and never looked back.

Uchimura, world all-around champion, was disappointed with his fault in the pommel.

"I am disappointed with myself," said Uchimura.

"We know we need to avoid mistakes if we want to beat China, but it's so difficult," he added.

"We have been watching Chinese since the Beijing Olympics. They are strong despite the retirement of (the Olympic all-around winner) Yang Wei."

Team USA, who led the qualification, was out of the podium early as Samuel Mikulak tumbled on floor and Danell Leyva fell off the pommel. Igor Pakhomenko's awkward landing on vault denied the Americans any medal chance. They finished fifth.

Uchimura was initially given around 13 points in pommel horse, but it was raised to 14.166. The change put Japan in second place, well over Britain and Ukraine.

"To be honest, I regret the result," said Uchimura. "But I am happy that we were promoted to the silver medal."

"For Ukraine, they think they can win a medal. I say sorry, but it's strange to say sorry for this, it's just a problem of scoring system."

Britain managed a place on the podium thanks to their strong performance on floor, which won them the apparatus high of 46.132 points.