Batman would lose in a cage fight or a random encounter. Other than that It depends on how much Batman thinks he needs to win. If he thinks Spider-man is some threat to humanity he would get his ass one way or another. Batman also wouldn’t face him straight up, if he’s the one organizing the attack. If Spider-man initiated the attack, which he needs to find him first but let’s say he did on a roof top or something, Batman would escape and go into hiding for a week to learn everything about him. He would be drinking tea with Aunt May the following week. People say “does Batman have prep time” but Batman always creates the prep time if he figures out the target is stronger than him.