Minato would use his space-time jutsu and go after Itachi. Itachi could not evade it and receive a beating by Minato. Itachi would use Katon Gokakyu No Jutsu but Minato would evade it easily. Minato again would use space-time justu but with a kunai this time but Itachi uses Crow Bunshin and prepares tu use Amaterasu but Minato evades it easily again but Minato didn't notice Itachi caught him in wires and use Amaterasu but Minato evades at the last moment but Amaterasu caughts his leg.
Minato use the speed of light and frees himself from Amaterasu and hitting Itachi with Rasengan. Itachi badly wounded uses Susano'o but Minato summons Gamabunta but Itachi attacks Gamabunta with Totsuka Sword sealing him but that's not a problem and Minato summons him again (he may do it again because the Summon justu is of temporay space).
Once summoned again he teleports with Gamabunta inside Susano'o crushing Itachi and if not Minato uses Rasengan and is all over.
(If Minato is caught with Amaterasu he isn't getting it off. Has he done anything that would even imply that thats possible? Has anyone done so? And being sealed inside the totsuka blade isnt like being teleported somewhere else. Its permanent genjutsu. The opponent is sealed in a genjutsu stupor for all eternity. And if Minato gets caught with wires.....their is no evading Amaterasu. He's done. you either get out of the casters sight instantly or its over.)
Would he be too fast for Itachi?
Please note this is not my comment. I'm posting it from another website. To a person to which I don't know.