David Miller and JP Duminy both scored centuries as South Africa overcame a real challenge from Zimbabwe to record a 62-run victory in their opening World Cup Pool B game in Hamilton.
Miller (138*) and Duminy (115*) rescued the Proteas' innings after they had been in trouble at 83 for four, as they put on a world record fifth-wicket stand of 256 to guide their side to 339 for four.
Elton Chigumbura's side, however, also showed that they would be a dangerous opponent for many sides with opener Chamu Chibhabha (64), Hamilton Masakadza (80) and Brendan Taylor (40) showing they were all highly competent international batsmen.
They had been on 214 for three and well set to push on for the final 15 overs before Taylor's dismissal effectively ended their resistance and they were bowled out for 277 in 48.2 overs.
"I'm happy with the result but credit must go to Elton and his boys, they really put us under pressure," South Africa captain AB de Villiers said.
"They also batted very well and probably just lost their way midway through their innings."
Zimbabwe had earlier exploited the slow nature of the pitch to put the World Cup favourites under pressure, but in reality they lost the game in the final 10 overs of South Africa's innings when they conceded a staggering 146 runs.
South Africa 339-4 in 50 overs (Miller 138*, Kamungozi 1-34)
Zimbabwe 277 all out in 48.1 overs (Masakadza 80, Tahir 3-36)