Lauritz van der Schyff scored two tries as Affies beat Grey College 29-18 in Bloemfontein on Saturday.
It was only the sixth time the Pretoria boys had won this fixture in 37 attempts. Grey have now suffered three consecutive defeats this season following losses to Monument and Paarl Boys'.
The first half belonged to Affies, who scored two tries through outside centre Henco Jordaan and flyhalf Eddie Fouché to lead 15-6.
The visitors crossed the line again in the first minute of the second half, through inside centre Van der Schyff.
Grey Bloem hit back with two tries from replacement centre PR Serfontein and replacement scrumhalf Rewan Kruger, but Affies sealed the result when Van der Schyff scored his second of the afternoon.
'We were very direct in attack and kept the ball well,' Affies coach Jaco Koch told SARugbymag.co.za. 'Our defence put them under a lot of pressure, and our breakdown play was very good. They came back well in the second half, but our players showed great character to win the game.'
'Affies were very good on the ground, and beat us to the breakdown,' said Grey College coach Wessel du Plessis. 'They were physical, and made the best of the opportunities they had, often scoring tries from our mistakes.'
Grey College – Tries: PR Serfontein, Ruwen Kruger. Conversion: Mario Vieira. Penalties: Neil Durow (2).
Affies – Tries: Henco Jordaan, Eddie Fouché, Lauritz van der Schyff (2). Conversions: Fouché (2), Ruan de Swart. Penalty: Fouché.