Ajax sensation Grant Margeman gave Amajita a deserved 1-0 lead after eight minutes with a powerful strike.
Thabo Senong’s manne had their tails up, but hitman Luther Singh and Keletso Makgalwa fluffed their lines with SA on top.
The Japanese hung in there and took their chance after the break when Koki Ogawa backheeled his team level four minutes into the second half.
The Blues dictated the game after that and Ritsu Duon’s clinical finish after a good build-up that caught the South Africans off guard sealed the game with 25 minutes to play.
Senong introduced Portugal-based striker Liam Jordaan and Platinum Stars forward Kabomelo Kodisang, who both injected some life into the Amajita attack, but they couldn’t get back into the game.