Pakistan pulled off a sensational 29-run win on the Duckworth-Lewis method after the match was reduced to a 47-over-a-side contest due to rain at Eden Park.
Pakistan, whose innings was twice interrupted by rain, were bowled out for 222 in 46.4 overs with skipper Misbah-ul-Haq hitting 56 and recalled wicket-keeper/batsman Sarfraz Ahmed scoring a run-a-ball 49.
Pakistan's left-arm pace trio of Rahat Ali (3-40), Wahab Riaz (3-45) and Mohammad Irfan (3-52) then bowled with venom to bundle South Africa out for 202 in 33.3 overs.
The victory gave Pakistan six points from five matches and revived their chances of a quarter-final place from Pool B while South Africa are also on six points from five games.
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Waqar said the team is gaining the same spirit of 1992 after defeats in their first two matches.
"I hope it turns out to be the same," said Waqar of the 1992 triumph which was also sealed in Australia and New Zealand.
"They lost early games but then came back strongly, they had the belief and (captain) Imran Khan had serious belief and I am hopeful that the same belief is coming into our dressing room. We are going to get better and better."
Waqar was not part of that 1992 team, withdrawn a fortnight before the tournament started with a back problem.
"We are gaining that belief that we can deliver. I am not going to think that far but, of course, we are heading in the right direction.