Sasuke. Unlike everyone else I will say why. If Minato glances his eyes it's over. Contract seal is useless as Sasuke will not need summons, and its not like he will get to touch Sasuke thanks to Susano'o. If Minato summons Gamabunta it will either get controlled or burned down with Ama, Food Cart Destroyer gets tanked with Susano'o THEN Gamabunta gets burned or controlled. His strongest offense aside from Gamabunta is Rasengan and a Kunai stab which get easily tanked with ribcage Susano'o. Hiraishin is the problem. Minato can warp all of Sasuke's projectiles such as Arrows and Magatama with space time barrier and dodge everything else with Hiraishin. Sasuke can't stop the space time barrier but he can counter Minato warping himself by burning up all the Markers present on the battlefield. This can be done by swamping the entire battlefield in Amaterasu forcing Minato to use Hiraishin to run away. Or course this depends on Sasuke figuring out Hiraishin, but considering his intelligence and readiness to use Susano'o, he should live long long enough to figure it out. Of course, he won't win 10/10 times as Minato is a smart guy and could always run away or use Shiki Fujin to force a draw.
I didn't take Minato's KCM into account for several reasons. It being usable only by a dead Minato and most of all it being featless being two. What's more, I can't transfer Naruto's feats due it being two different types of chakra, having two different properties, meaning Minato may be incapable of what Naruto is capable of. If he has Naruto's feats and his KCM is usable, them Minato wins.