A scene from Keanu Reeves' directorial debut Man of Tai Chi. Photo provided to China Daily

Reeves' action scenes are dense. He battles Chen in hand-to-hand combat in the final "super fight", as he calls it. He did most of the 10-minute sequence himself but called in stuntmen for some of the dangerous moves because he has a neck plate.

Chen is the film's biggest star and fights for much of the 100 minutes.

The 30-year-old from Sichuan province started training at age 8 and worked in many Hollywood movies as a choreographer, stuntman and trainer. He and Reeves became friends while training eight hours a day when making The Matrix.

Chen calls Reeves "the most hard-working and interested in Chinese culture among all star pupils". He told Reeves to watch Bruce Lee and Jet Li films every night and combine what he saw with what he was taught. The pandas, landscapes and food of Sichuan were frequent conversational topics. Reeves wrote the preface for Chen's 2005 autobiography.

"Perhaps we bonded because I tortured him more than others," Chen says, jokingly.

"It's difficult to describe how you establish friendships. You just feel connections when you talk about family and share jokes and perspectives."

Director Keanu Reeves promotes 'Man of Tai Chi'	Keanu Reeves promotes director debut in Hangzhou	Keanu Reeves makes director debut with modern kungfu film