Atom takes a pounding but wins his first fight when the other robot malfunctions. They're instantly offered another fight for a little more cash. Max spends more time on the robot, installing parts from the other broken machines including the voice recognition software from 'Noisy Boy'.
Charlie sees his son dancing with the robot and thinks it's cute. He asks him to do it before every fight. In return, Charlie will shadow box with Atom to teach him how to fight ... even though Atom just copies his movements so doesn't really pick up too much.
Atom starts to win a few more fights. Charlie is able to pay back Bailey for the rent ... and soon they are offered a league match against a two headed machine.
Before the tournament, the owners of Zeus arrange a meeting with Max and Charlie -- and offer $200,000 for the robot. Charlie wants to take the offer - but Max is adamant that they won't sell. The offer will expire when the fight starts.
In the match-up, Atom again takes a pounding, but Charlie uses his fighter's instinct and looks for a weak spot - a chink in the other robot's shoulder armour. Atom takes the fight to his opponent, who soon self-destructs.
Max then grabs the mic and challenges the owners of the mighty Zeus to a fight. The crowd, for some reason, respond to the annoying kid and everyone backs the chant.
Outside, they are found by Ricky - who comes good on his promise to beat Charlie within an inch of his life (although, to be fair, this is a kids movie and it doesn't look that bad). They take back all the money - and leave them behind. Atom didn't even lend a hand. Some fighting robot he turned out to be.
Charlie takes Max back to his Aunt. After a little soul-searching and loneliness ... and the offer of the fight against Zeus, he returns to pick up Max. The Aunt allows Charlie to take him back for one more day.
It's fight time. Ricky shows up and offers the bookies outside $100,000 that Atom won't see round two. They take his bet.
Atom takes a pounding and is knocked down several times in the first round, but manages to make it through. The bookies surround Ricky to claim back their money, and he is escorted outside.
The fight isn't going so well for Atom, although he does manage to sneak in the odd good punch and is holding in there. Later in the fight, his voice recognition chip is damaged. In the fifth and final round, they have no choice but to use the shadow function - with Charlie ringside showing him the moves.
Charlie plays 'rope-a-dope' Ali-style as Zeus's energy drains - then springs into life and knocks the other robot senseless ... but it's all too late to get a knockout. The Japanese robot designer is going mental and smashes his fists through the glass control screen.
The bout is over, and Zeus is the unanimous winner ... although the crowd cheer for Atom, the unlikely hero, and he is awarded the turkey prize of 'The People's Champion'. Charlie and Bailey look like they'll end up together.
The contest is over -- Atom didn't win, and is probably too beat up to ever fight again. Max will return to his Aunt never to see his dad again unless there's to be a huge court case. But at least Ricky got sorted out.