MacGyver arrives in his loft and discovers he has an uninvited guest: ex-con Earl Dent. Dent asks MacGyver to help him training for an upcoming boxing match. Earl was a heavyweight champion before he went into prison and held his own against Crazy Eddie Jackson. Now Jackson is out and has set up a match with Earl. MacGyver refuses, insisting that he hates violence. Earl seemingly gives up and asks MacGyver to come with him as a character witness for the Department of Children's Welfare.
At the department, Earl introduces MacGyver to his daughter, Veronica. She insists that Earl call him Ronnie and mouths off to him. Earl and MacGyver meet with the department agent, Clarice Miller, who goes over Ronnie's record. She explains that since Earl has been in prison, the girl has been and out of foster homes and has a record of minor criminal activities. Clarice warns that Ronnie needs a stable home environment. Earl volunteers MacGyver to supply both of them with a home and then explains that he will be boxing in a $25,000 prize match and MacGyver will be training him. MacGyver isn't happy at being volunteered against his will, but reluctantly agrees so father and daughter can remain together. Clarice warns that if Earl doesn't make enough money to provide Ronnie with the necessary support, she'll be taken away from him and put back into a foster home. As they leave, Earl admits that no gym will take him and MacGyver is his only hope. Outside, they find Ronnie stealing candy from a vending machine. When Earl tries to discipline her, Ronnie insists that he has no right to lecture her given his criminal background.
MacGyver, Ronnie, and Earl go back to the loft and MacGyver starts making training equipment out of odds and ends. Earl and Ronnie go to get groceries. As they're tossing packages back and forth, Earl bumps into a car and the man takes offense. Ronnie defends her father and afterward, says he should have taken him. Earl says that there are other ways to handle things. He notices that she's stolen some wrestling cards from the grocery store and says she'll have to take them back. When she wonders why Earl wants to be a father to her again, he admits that he messed things up and wants to make up for the years they spent apart. He goes back to pay for the wrestling cards before someone realizes Ronnie stole them.
Earl and Ronnie return to MacGyver's apartment and discover he's made a boxing machine out of old gloves and pistons. MacGyver turns the remote over to Ronnie to start training her father and then leaves them alone. Bart Riggins and his bodyguard, Bailey, pay a visit. Riggins reminds Earl that he used to be his manager but Earl never listened to him. Earl brusquely sends Ronnie upstairs so she doesn't hear Riggins reminding him that he's agreed to throw the fight in the eighth round. As MacGyver returns, Riggins hints at what will happen to Earl if he reneges on their deal and leaves. They realize that Ronnie has run away and go looking for her. MacGyver finds her and admits that he ran away once when his grandfather sent him away. He explains that Earl sent her away to protect her and that Ronnie should give him a little time.
When earl catches up to them, Ronnie accuses him of running away from a fight based on what she overheard of his conversation with Riggins. Earl takes her and MacGyver to a gym and shows her the poster of his third-tier match with Crazy Eddie. Ronnie is more interested in Herman the German, a famous wrestler. When she approaches him for his autograph, Herman gives her two ticket. Earl isn't impressed, insisting that professional wrestling is fake. When Ronnie asks Earl to show her the gym, he warns her that he's managed to burn his bridges behind him and the gyms won't let him in. He takes her inside and they find Crazy Eddie sparring. He taunts Earl about the fact he's a deadbeat dad and says he'd be glad to fight Earl for free and forego the $4,000. Earl jumps into the ring to take him on and MacGyver tries to break them up. He gets hit in the nose for his efforts and Eddie's manager Stimson breaks up the fight. As they go, Ronnie manages to steal a pair of gloves from a boxer's bag.
That night, Ronnie apologizes to Earl for doubting him and admits that she really believes he wants her around. Outside, MacGyver demands to know why Earl claimed he was getting $25,000 for the match but Crazy Eddie said it was only a $4,000 prize fight. Earl admits that he's going to take a dive on Riggins' behalf and claims it'll only be the one time so he has enough money to support Ronnie. MacGyver warns that Ronnie will figure it out and that Earl doesn't deserve custody of his daughter.
The next morning, Earl is training when Ronnie comes in and admits she stole the gloves. He refuses to talk to her and she runs out. However, later he goes to Riggins' machine ship and bookie operation and tells his former manager that he's not going to throw the fight. Once Earl is gone, Riggins tells Bailey to kidnap Ronnie so they can use her as leverage against her father.
Earl goes back and tells MacGyver what he's done. Ronnie comes back and explains that she took the gloves back despite Earl's silent treatment, and he says he knew she'd make the right decision. They train for the next two weeks and Earl is ready to fight. On the day before the match, Riggins and Bailey wait until MacGyver leaves and then break in at gunpoint and take Ronnie. When Riggins tells Earl to take a dive like they originally planned, Ronnie realizes her father was willing to do anything for her. The crooks leave with Earl's daughter.
On the day of the match, Earl and MacGyver arrive at the ring and MacGyver wonders why Ronnie isn't there to cheer on her father. The match begins and Earl takes a beating. MacGyver finally realizes that Ronnie isn't there and Riggins is using her as a hostage against Earl. He convinces Earl to tell him where Ronnie is, at Riggins' operation across the street.
MacGyver breaks into the machine shop and climbs down from the ceiling to a forklift crane. Ronnie sees him and asks Bailey to turn on the radio so she can hear her father's match. Bailey obliges and MacGyver frees Ronnie. When Bailey sees them and starts shooting, MacGyver moves the crane forward as protective cover and smashes the arm through the upstairs office window where Riggins and Bailey are listening to the game. Once they're trapped, MacGyver takes Ronnie to the arena just as Earl goes down. Ronnie yells at her father to get up and he gets to his feet and knocks Crazy Eddie down. The judges rule in Eddie's favor and Earl says that it's okay, as Ronnie admits that she loves him.
After the match, Earl is in the ring worrying about how he'll get the money to satisfy Child Services. Ronnie wants to stay with her father no matter what. Herman the German comes in and tells Earl that he's impressed with the boxer's showmanship and wants to pay him a $30,000 advance to work for him as a professional wrestler. Ronnie quickly accepts and convinces Earl to take on the job.