Ngezana powered a bullet header from a Mduduzi Shabalala free kick into the back of the back of the net as early as the eighth minute.
Amakhosi should have doubled their lead in the 18th minute when Christian Saile was clean through on goal but the winger was denied by home goalkeeper Salim Magoola
Richards Bay were then dealt a severe blow just a minute later as they were reduced to 10 men when Mogoola was adjudged to have a deliberately handled the ball outside the box and was shown a straight red card.
Chiefs then piled on the pressure as the first half came to a close and striker Bonfils-Caleb Bimenyimana crafted a superb volley that was well-saved by replacement shot-stopper Neil Boshoff.
It was the Soweto giants who again started strongly after the halftime interval with Boshoff called into action to deny Keagan Dolly and Yusuf Maart.
Substitute Kamohelo Mahlatsi then had an opportunity to put the result beyond doubt but he lifted his effort over the cross-bar.
Amakhosi were having all the possession with a man advantage but were rather wasteful in the final third of the pitch but it did not matter as they claimed maximum points.
The home team offered little going forward with a 10 men and it is now seven games without a win for the KZN outfit.