Undisputed II: Last Man Standing
(2006)

It turns out that George "Iceman" Chambers (Michael Jai White) was set up to be arrested on false drug charges by Russian mobster Gaga (Mark Ivanir) and his manager Phil (Ken Lerner) in order to fight prison champ Uri Boyka (Scott Adkins), whose undefeated streak has affected the illegal betting, costing Gaga money.  Phil went along with the plan since he thought it would make them a lot of money.

The first fight almost goes to Chambers but his cell mate Stevie is forced to give him drugged water so Uri Boyka will win again, costing everyone who bet on Chambers.  Stevie kills himself over his guilt.  Phil, becoming greedy, decides to let George rot and asks for more money in exchange for silence.  Phil does not get far as Gaga has him killed since he is a liability.

Forced into a rematch, George is trained by Crot/Nikolai (Eli Danker) who is an ex soldier.  He tells George he went to prison for his brother and was heavily tortured.  He tried to escape resulting in a death of a guard and his confinement to a wheelchair.  Nikolai only wants to see his niece but will never ask her to see him in prison.

The second fight begins and after an extended battle George gets Uri leg locked and proceeds to break it, winning him the match.  George is released and given a cut of the profits but tells Gaga he won't forget what he did to him.  About to leave, George gets an attack of conscience and uses his new winnings to negotiate with the warden for the release of Nikolai.

The last scene is Nikolai and George at the train station so Nikolai can meet his niece.  He and his niece embrace as George walks off, a free man once again.

 Thanks Spectre!