Southpaw Billy “The Great” Hope (Jake Gyllenhaal), is a professional boxer in Light Heavyweight with an Orthodox posture, with a record of 42W0L-0D and a living in New York City together with Maureen McAdams and their one daughter Leila (Oona Lawrence). When he is battling Darius Jones (Cedric D. Jones) at Madison Square Garden, Maureen is terrified as Billy is hit with a number of devastating blows on the face that result in massive bleeding out of his eye. Despite suffering from severe injuries, Billy wins the match by knockout. He retains the title of lightweight heavyweight.
As the media focuses on Billy, Miguel “Magic”, a young upstart boxer ( Miguel Gomez) calls him to take on him. Maureen is concerned about Billy’s safety once he returns home and encourages him to stop. At the Hope house, Maureen talks to Billy’s manager Jordan Mains ( 50 Cent) and is not happy with his plan to get Billy to agree to a two-year deal that will last for three fights.
Billy and Maureen attend a fundraiser ball, at which Billy delivers a speech in recognition of Maureen as well as Leila and Jordan and his fellow guests. Miguel is there too, and when Billy is leaving, Miguel goads him by insulting Maureen and threatening to take his titles away from him, which leads to a brawl. Hector’s brother Miguel fired a shot, and Billy notices. Maureen is dead. Hector runs away, but Maureen is alive in Billy’s arms.
Billy begins abusing alcohol and other drugs. Jordan proposes to Billy that he sell his home to ease his financial woes. Jordan arranges for Billy a fight against Kalil Turay. Billy is battered to the point that his opponent decides to throw in the towel. Blinded by damage due to headshots, Billy hits the referee in the face. Billy is suspended for one year and has no income, while he owes the referee and the networks for damages. The home and possessions of Billy are taken and taken away. Both Jordan and longtime trainer Eli Frost abandon him to collaborate with Miguel.
Billy crashes his car into the tree outside his home at night. Leila realizes that Billy is bleeding to the ground, and she calls 911. Leila Rivera, Naomie Hari is the Child Protective Services Officer who wakes Billy awake on the floor. With nowhere left to go, Billy visits the Wills Gym where there is a former boxer Tick Wills ( Forest Whitaker), who has lost sight in his left eye due to his last fight left him injured. Billy is desperate for Tick to help him get back to his feet however Tick knows about his drug problems and declines to coach him. Tick gives Billy the job of a janitorial assistant.
Billy is able to meet with Angela to meet Leila. However, Leila blames him for the problems they have and is unwilling to visit him. Billy goes back to the gym and takes the job of janitor. He becomes friends with one of the boys known as Hoppy ( Skylanbrooks) and a boxer as well, while working in the gym. Hoppy’s father abuses his mother, which is reported to Tick. In the process of making amends, Billy continues visiting Leila, and his persistence wins her over. Following the success of a charity match, Billy is visited by Jordan. Miguel, the champion of Kalil Turay, is the manager of his. Jordan is eager to set up an event between them within the next six weeks since Jordan is aware that Billy isn’t going to have enough time to train. Tick does not believe that Billy is just seeking revenge.
Tick informs Billy that Hoppy was killed while trying to protect his mother from the father who killed him. Deploring that he was unable to help Hoppy, Tick decides to assist Billy train for the upcoming fight. The judge gives Billy custody of Leila after noticing his efforts to change his life. Leila moves in with him. Billy goes to Maureen’s grave and informs Leila that he’ll fight back. He also grants Leila the wish of her to remain with him.
The night before the fight Angela brings Leila into the dressing room, where they can watch the fight on television. Miguel is the first to take the upper hand. Round after round, the fighters exchange furious punches. Miguel is then rude to Maureen, causing Billy to lose focus. Billy is unable to control his temper and nearly ends the fight. Tick off Billy not to let Miguel take control of his temper. Billy controls his anger and , in the final round wins the fight against Miguel. In the last few seconds, Billy blocks a jab from Miguel and then lands a punch at the face, before turning south and, after a furious uppercut, knocks Miguel to the canvas. Miguel stands up in the closing second and both corners are filled by two teams’ staffs.
Billy is declared the new champion despite a split decision giving Miguel his first chance to win. After a short pause, Billy collapses and thanks Maureen before officially entrusting himself to Leila. Tick and his teammates raises him up on their shoulders while he shuts his eyes tearfully and smiles. Leila and Billy are seen together in the dressing room after the battle. They hugged for the first times since Maureen’s loss. Billy affirms that Maureen would be proud of her, and she tells him she has a special relationship with him.