Japan's Shinnosuke Oka capitalised on errors by the top contenders and held his nerve to fend off a late challenge by China's Zhang Boheng to win the men's all-around gold medal at the Paris Olympics on Wednesday.

Zhang trailed by just 0.233 of a point to take silver and his countryman Xiao Ruoteng claimed bronze.

The tense final came down to the last apparatus -- the horizontal bar -- and 20-year-old Oka maintained his poise under intense pressure to finish with a total of 86.832.

First-time Olympian Oka strode into Bercy Arena in the shadow of his more celebrated teammate, Tokyo all around champion Daiki Hashimoto. .

But with Hashimoto and Xiao both faltering during the earlier rotations, Oka kept his wits about him as he produced spectacular routines on all six apparatus to put everyone else in his shade as he picked up his second gold in Paris after helping Japan to victory in the team final two days ago.