While the visitors managed to stay in touch in the early stages, holding the hosts to 3-3 in the first few minutes, the Proteas soon took control and romped to a 20-7 lead at the end of the first quarter.
The Zimbabweans exerted more pressure after the break but South Africa maintained their composure and extended the margin to 37-20 at half-time.
Their neighbours gradually improved throughout the game, but the South Africans were relentless on attack and the gap continued to widen, with the hosts holding a convincing 50-30 advantage going into the final quarter.
The SA team had their best stanza in the last 15 minutes, drawing further ahead to take full points from the match.
“It wasn’t easy. It was a physical game, but we knew it would be and we were prepared for it,” said Proteas goalkeeper Phumza Maweni, the Player-of-the-Match.
“I think we need to be more physical because every game is going to be like this, and we need to be prepared for everything.”
Earlier on the opening day of the Diamond Challenge, the national President’s XII side defeated Uganda 55-50 in a hard-fought contest.
The President’s XII settled in second place in the standings, behind the Proteas on goal difference.
Though Zimbabwe, ranked 16 places below the Proteas, were unable to put up much of a challenge, South Africa were expected to face stiffer opposition against the Ugandan outfit, who finished third last year, in their second match of the annual tournament on Monday night.
The President’s XII were scheduled to face Zimbabwe in their second encounter later in the evening.