Georgia stunned the Boks with an early score from a driving maul in the opening five minutes, but the world champions took it on the chin, got their legs back and scored four unanswered tries on the trot.
Two of those came from Van der Merwe, one of three players making their Test debut in the match, while another debutant, Boan Venter, opened the scoring.
Canan Moodie also finished in style following a blistering break by scrumhalf Grant Williams. Unfortunately Sacha Feinberg-Mngomezulu missed the first three conversions.
More to follow…
Scorers:
Springboks (22) – Tries: Boan Venter, Marnus van der Merwe (2), Canan Moodie. Conversion: Sacha Feinberg-Mngomezulu.
Georgia (10) – Try: Vano Karkadze. Conversion: Luka Matkava. Penalty goal: Matkava.