prime bugner wins this by comfortable UD.he is taller,had longer reach,superior jab,faster hands and far better footwork.mavrović had a good chin and bugner was very average puncher, so i think mavrović would survive all 12 rounds.
Bugner wins, Bugner was also a higher level than Mavrovic who once fought taxi drivers, the fight with Lennox Lewis was an exception and in that fight Mavrovic showed nothing spectacular except a great chin...
The sort of fight that an unmotivated Bugner could blow. But providing he is even a little focused he would win a comfortable decision. As mentioned, the Lewis fight really was Mavrovic fighting at a level far above anything he had previously shown, and he still lost comfortably.