Hiruzen Sarutobi and Orochimaru had a pretty big fight back in the day and Orochimaru was declared the victor. It can be argued that Hiruzen Sarutobi only lost because he was old and others can counter with the fact that Kishimoto hadn’t thought of Orochimaru’s full power at the time. Regardless, it was a good fight, but I was always on Orochimaru’s side. He’s proven time and time again that he is a fierce combatant with his large array of jutsu and abilities. I don’t see Hiruzen being able to take on Orochimaru in his prime. Orochimaru wins.