Damn, that's a good one. However, what if he can catch Saitama because he's so fast? I'm seriously asking because I don't know if this is even possible for Saitama to do. Like is it possible to be so fast that Goku can't get you with instant transmission?
Also, we both know Goku would never want to win this way, Although he might do this if he has no other options. This was a great point by the way. Can't believe I forgot about it lol.