Question: When did the heavyweight boxing championship match, for which the Zaire 74 concert was intended to be a major promotional event, actually take place?  
Sentence (from "Aniversario: Never Compromise"): Another major match during the event saw former Campeones de Parejas, Amasis and Ophidian, end their nineteen-month storyline rivalry in a Sarcophagus match.
Relevant evidence: No