Smaug The Dragon vs Movie Optimus Prime

In character

Winner by KO, incapacitation or death

Random encounter

Fight takes place at an unpopulated city block at night

Standard abilities and gear

Who'd win? For what reasons?

Prime, handily.

Optimus. I don't think he would be affected by Smaug's fire to the point of incapacitation.

Optimus already beat a dinosaur that is about as bug as smaug but much more durable with better firepower,

Prime 'cause feats.

No, because he's got the touch!!!!!!!!!!!!!!!!!!!!!

He basically came into the world on some meteor type-sh*t. Resisting the heat from re-entry.