New Zealand 207 for 2 (Guptill 103*, Latham 64, Phangiso 1-37) beat South Africa 204 (Behardien 70, Bracewell 3-31) by eight wickets
Scorecard and ball-by-ball details
A career-best 3 for 31 from Doug Bracewell cancelled out a fighting 70 from Farhaan Behardien, and set New Zealand up for a dominant, series-leveling victory in the second ODI. On a slow surface, New Zealand's attack squeezed and then strangled South Africa with tight lines, pace off the ball and some reverse swing, none of which the home side could replicate.
New Zealand cantered to victory without many concerns. Martin Guptill and Tom Latham starred in the highest first-wicket partnership for New Zealand against South Africa, beating the previous record of 114 set by Latham's father Rod and Mark Greatbach at the 1992 World Cup. Guptill went on to score his ninth ODI century and his first against South Africa, with the runs scored authoritatively and all around the ground.
South Africa's first error came at the toss when AB de Villiers decided to bat first despite chasing being the preferred option in Potchefstroom. Their next mistake was the over-eagerness of the openers, who both fell playing aggressive shots and exposed the middle order earlier than they would have liked. New Zealand could see straight through South Africa and plucked most of their middle order in the period between overs 16 and 33 before clipping the tail in the last five overs.
South Africa's twin collapses - 4 for 66 in the middle period and 4 for 16 at the end - were held together by Behardien, but even he could not get really get going on a pitch New Zealand understood better.
Pace seemed puerile, but Adam Milne enjoyed the early success. He steamed in and offered width to Hashim Amla, who threw his bat at it, forgot to move his feet and was caught at third man. Milne could have had Rilee Rossouw out two balls later when a low full toss was driven straight back to him but he could not hold on. He did not have to wait too long to make another incision, though.
Morne van Wyk tried to cut the last ball of Milne's second over and chopped the ball onto his offstump. As if losing both openers inside four overs did not put enough pressure on South Africa, that was immediately followed by the only maiden over of the innings, delivered by Ben Wheeler.
South Africa's two cleanest hitters were at the crease but neither de Villiers nor Rilee Rossouw could really get going. Rossouw looked comfortable and timed the ball better than any of this team-mates but Doug Bracewell and Ish Sodhi were difficult to get away and ultimately, that frustrated him. After a six-over stretch in which only 21 runs were scored, Rossouw tried to clear mid-off off a full delivery from Bracewell, but found only Kane Williamson.
David Miller had an opportunity to end his lean run, which has now now reached ten innings without an ODI half-century, but never looked comfortable. He was surprised by a Bracewell delivery that reared up a touch, closed the face of the bat too early and got a leading edge to short cover. De Villiers was also done in by some extra bounce, from Grant Elliot, and was caught at mid-wicket, as South Africa's trouble deepened.
By then, Behardien had made some measure of conditions and realised he would need to bat responsibly. He searched for singles, even though he seldom found them, and managed not to get frustrated. Almost. After 11 boundary-less overs, he pushed a delivery back at Milne and could have been caught in the follow through but with power behind his push, Milne had to react quickly and could not hold on.
The exasperation still hung over South Africa. David Wiese only lasted five more deliveries before he was given out lbw off Sodhi. Replays showed the ball had pitched marginally outside leg stump.
With only the bowlers to come, Behardien tried to up the ante. He struck the innings' only six with a pull over mid-wicket off Sodhi to bring up his half-century off 62 balls, but was soon forced to quieten down again with the introduction of Colin Munro followed by Wheeler and Elliot.
Another lean six-over period followed with just 16 runs scored, and with the innings into the final five overs, Behardien felt he had to do something. However, he holed out to Bracewell, trying to drove down the ground, to leave the seamers to bat out the remaining overs. A trio of run-outs saw South Africa finish three balls short and well short of a competitive total.
De Villiers tried to be innovative in his defence and opened the bowling with a spinner, Aaron Phangiso, but Guptill made a mockery of that plan. He took four boundaries off Phangiso's opening two overs and gave one chance - a return catch which Phangiso could not hold on to.
Dale Steyn replaced Phangiso and searched for swing without much success. Then Wiese took offer but bowled a poor line and strayed onto the pads. Steyn tried again from the other end but went too wide. All the while, Guptill and Latham took advantage, steering the ball behind square, and driving and cutting with confidence to bring up New Zealand's fifty inside nine overs.
Imran Tahir managed to slow them down and could have had Guptill out twice - once when he was on 37 and offered a return catch and a second time when he was on 39 and put down at long-off - but New Zealand made steady progress. Latham's fifty came first, off 57 balls, and Guptill's soon followed, off 86 balls.
New Zealand lost their first wicket when Latham top-edged Tahir to Rossouw at deep square leg but by then, the game was already won. Guptill batted through to the end, when his race to reach his hundred was against the total and not the bowlers. Guptill was on 97 when New Zealand needed four to win and on 99 when New Zealand needed just one. He sent a loopy full toss to the extra-cover boundary to seal his century as well as the win, setting up for a finale on Wednesday, which New Zealand will be more confident going into than South Africa.
Jimmy Neesham, who did not play this match, earlier in the week warned that New Zealand had become expert comeback kings once they have had a chance to assess conditions. New Zealand lost the first ODIs in both England and Zimbabwe before winning the next two matches and in the case of Zimbabwe, the series. South Africa will be aware that the same could happen in Durban.

Firdose Moonda is ESPNcricinfo's South Africa correspondent