itachi is a badass but ntn he can do can stop minato.
Itachis genjutsu is very good counter to Minatos abilities. Itachi would win in my opinion.
This is scenario where Itachi wins.
1. Minato and Itachi meet each other.
2. Minato dont looks into Itachis eyes, but looks at the rest of his body including his hands. Minato throws his kunais.
3. Itachi traps Minato in his finger genjutsu - simple gesture is enough. Minato dont know that, becuase thats how Itachis gen works - one dont know that hes trapped in it until weird shit starts to happen.
4. Minato fights fake Itachi and hits him with Rasengan. He thinks that the battle is over and suddenly he feels strong pain in his back. Itachi that was defeated seconds ago turns into bunch of crows, Minato tursn around and... surprise! There is Itachi holding kunai in his hand.