Stellenbosch left the Sugar Ray Xulu Stadium empty-handed on Saturday afternoon after AmaZulu claimed a 1-0 victory through a penalty.
The first half started cautiously, with both sides trying to find their rhythm in a tightly contested opening.
Sage Stephens was called into action on a couple of occasions, using his experience to keep the danger at bay.
At the other end, Sinoxolo Kwayiba had a golden opportunity to put Gavin Hunt's troops in front, but Olwethu Mzimela produced a good save to deny him and keep the scores level.
Arthur Zwane's team finally made their pressure count in the 59th minute after Athini Maqokola was brought down inside the penalty area, prompting the referee to point straight to the spot.
Usuthu were awarded a penalty, and Thando Ngwenya stepped up with composure and handed his side a breakthrough.
The final whistle sealed a narrow win for AmaZulu, ensuring they claimed all three points.