Minato will win this fight nine times out of ten, think about this for a second, what attack does Kakashi have that can actually hit Minato besides Kamui? Nothing. Minato was able to avoid being sucked up by Obito, he was fast enough to escape Kamui before it even hit him.
Minato has barrier seals which can defend against any of Kakashi's large scale ninjutsu, Minato is also considered the fastest shinobi in all of Naruto, not just because of FTG, but because his basic speed and reflexes are insane. I love Kakashi, he's one of my favorite characters, but he's far from surpassing Minato, especially since we don't even know all of Minato's abilities at this point.