For this battle, I have to go with Captain America (Steve Rogers). He has a lot more fighting experience than Iron Man (Tony Stark). Even though, Iron Man has better technology, Captain America would find a way to take him down.

However...In some comic stories, It says that Iron Man records every single move that Captain America has ever done, so he can predict what move Captain America is going to do next, before he even does it... So if it's based off this, than I have to go with Iron Man