The Valke proved unstoppable in the Namibian capital running in 10 tries to the two of the home team with flank Mabuza and left wing Damons scoring three times each. The match presented the home team with their final chance to clinch a victory in this year's competition having suffered six straight defeats.
But the Valke would have remembered how the Namibians scored a surprise victory over them in Kempton Park last season and will have been determined to prevent history from repeating itself.
And they did so with ease as they rattled up a 32-0 lead at halftime with Mabuza, fullback Juandre Nel, Damons (3) and flank Jan Venter all dotting down.
Mabuza got his second just after the restart before the Windhoek Draught Welwischias opened their account with a score by hooker Gerhard Thirion.
Valke right wing Coert Cronje sped over on the hour for the Valke before a try by home centre Millan van Wyk and a Lorenzo Louis conversion made it 49-12. Nel got his second try for the Valke on the final whistle and Anrich Richter landed the conversion to wrap up a comfortable win.
Windhoek Draught Welwitschias - Tries: Gerhard Thirion, Millan van Wyk. Conversion: Lorenzo Louis.
Valke - Tries: Thabo Mabuza (3), Juandre Nel (2), Rodney Damons (3), Jan Venter, Coert Cronje. Conversions: Jan Truter, Anrich Richter (2).