“I should've stopped the fight with your father. I'm stopping this one...”

[When Donnie's left eye is shut and he's in the corner after the big knockout]
Rocky: I should've stopped the fight with your father. I'm stopping this one now.
Donnie: Don't, okay? Let me finish. I gotta prove it.
Rocky: Prove what?
Donnie: I'm not a mistake.
Rocky: Look at me. I never got a chance to thank Apollo for helping me out after Mickey died, but it's nothing compared to what you've done. You taught me how to fight again and I'm gonna go home and I'm gonna fight this thing, but if I fight I want you to fight too. I want you to go across this ring and knock that son of a bitch down. Can you do it? Say it.
Donnie: I'm gonna knock that son of a bitch down.
Rocky: I know you are. You know why? Because you're a Creed and I love you, kid.