After an opening try by team-mate Craig Barry, Maties wing Duncan Saal ran in a hat-trick of tries as the visitors took control of the match.
Stellenbosch led 23-9 at the break, but Ikeys hit back in the second half when Nyasha Tarusenga crashed over for their only try of the night.
However, Saal completed his hat-trick as Maties crossed for three tries in the final 10 minutes for a resounding win.
UP-Tuks scored three tries without reply to defeat Wits 25-9 in Pretoria after leading 15-9 at the break.
Wits played a high tempo game in the first half, but Tuks’ defence was sound throughout the encounter.
After Tinus de Beer (Tuks) and Warren Gilbert (Wits) swopped penalties, Tuks wing Dewald Naude crossed for the opening try of the match.
Gilbert kicked two more penalties before Tuks captain Chris Massyn scored their second try.
The pace slowed in the second half, but utility back Franco van den Berg completed the scoring for Tuks with a try late in the game.
The University of Johannesburg ran rampant to score a bonus-point win over home side CUT in Bloemfontein, winning 73-20.
It was one-way traffic in the first half as the visitors ran in six tries to take control of the match.
Besides some poor tackling by the Ixias, the UJ forwards dominated proceedings, allowing their potent backline to run circles around their opponents.
For a lengthy period in the second half, CUT showed better commitment to keep the visitors at bay before UJ broke out to score three more tries in the closing stages.