The Brazilians went ahead as early as six minutes into the match when Sphelele Mkhulise profited from an error by Royal AM defender Ayabulela Maxwele to beat goalkeeper Zakhele Ngcobo.
With the visitors from KwaZulu-Natal putting up a stern challenge, Khuliso Mudau finished them off with four minutes to go in a follow-up to Peter Shalulile's failed attempt.
Sbangani Zulu then headed in Royal AM's consolation goal in stoppage time as they pressed for an equaliser.