Ali star Jamie Foxx says the role has helped him prove his acting skills.
The comedian plays boxer Muhammad Ali's troubled aide Drew 'Bundini' Brown in the new film.
Foxx is best known in the US for TV shows like Any Given Sunday and the Jamie Foxx Show.
"I've benefited more by doing drama right now because it's not expected," he said.
"Because if you get a person who doesn't know that you do comedy and they still enjoy the performance, then that means it's genuine."