Play is set to resume at 6.45pm, with both teams playing 43 overs, after rain stopped play at Eden Park with South Africa on 216 for three after 38 overs.
The covers came off a short time ago.
After an hour long delay, overs have been reduced with Duckworth-Lewis coming into play - possibly calculating a target for New Zealand.
The ICC conditions and rules for the tournament states:
12.1 Law 12.1 e) "Every effort will be made to complete the match on the scheduled day with any necessary reduction in overs taking place and only if the minimum number of overs necessary to constitute a match cannot be bowled on the scheduled day will the match be completed on the reserve day."
12.1 Law 12.1 f) "If the match has started on the scheduled day and overs are subsequently reduced following an interruption, but no further play is possible, the match will resume on the reserve day at the point where the last ball was played."
Former New Zealand allrounder Dion Nash looked on the bright side of the rain.
"Hopefully it gives the Black Caps a little bit of a pause just to get their thoughts."It was getting away on us a little bit so we'll see. Sometimes these breaks can work in your favour, and de Villiers in particular is looking dangerous."
Nash said South Africa looked like scoring in excess of 300.
"That would be a competitive total. I don't think it means we're out of the game, but I think South Africa would be disappointed if they didn't make 300.
"But I think the Black Caps have bowled beautifully and it looks like it's going to be a great cricket match at this point, let's wait and see."
Auckland man Nikhil Zaveri, a senior manager of a healthcare company, said if the game was rained off today, he'd take another day off work.
"I told the boss if there's rain today I'm not coming to work tomorrow, simple as that," he said.
"I'd stay up all night if we were playing at night. Cricket always comes first, get your priorities right."