Complex sentence: Sensing trouble, Futch moved to block (Ali-Foreman ref) Zach Clayton as referee by enlisting the aid of Philadelphia Mayor Frank Rizzo who refused to let Clayton out of his duties as a Philadelphia civil service employee to go referee the fight.
Split into simpler sentences: Sensing trouble, Futch moved to block (Ali-Foreman ref) Zach Clayton as referee by enlisting the aid of Philadelphia Mayor Frank Rizzo. The Mayor refused to let Clayton out of his duties as a Philadelphia civil service employee to go referee the fight.