The Ghana striker's family issued a statement on Wednesday - the day of the match - to deny any involvement in the disappearance of rapper Castro and friend Janet Bandu.
Castro - real name Theophilus Tagoe - and Bandu are said to have gone missing while using jet skis during a holiday with Gyan's family at a resort in Ada, Ghana, in July.
No bodies were recovered following a search, prompting some media outlets to speculate over what might have happened to the pair, with some claims linking Gyan to an alleged "spiritual sacrifice".
But a statement read out by lawyer Kissi Agyabeng dismissed what it described as "absurd" and "ludicrous" allegations surrounding the 28-year-old.
Miroslav Stoch doubled the advantage by blasting into an open goal, and Gyan got his own name on the scoresheet 12 minutes after the break.
Second-placed Al Jazira returned to winning ways after being held by Al Fujairah last time out, beating Emirates 3-0, while Al Nasr suffered the first defeat of the season at Al Shabab, losing 2-1 and seeing Mahmoud Khamis dismissed.
