Centurion: AB de Villiers starred with the bat and Wayne Parnell with the ball as South Africa bounced back in contention for the Champions Trophy to beat New Zeland by five wicket at SuperSport Park on Thursday.
The hosts were beaten by Sri Lanka in their first game, but bounced back with a professional performance to dismiss New Zealand for just 214 in 47 overs.
Parnell claimed a career-best 5-57 to restrict New Zealand to a low score. Dale Steyn and left-arm spinner Roelof van der Merwe shared two wickets each.
Ross Taylor top-scored New Zealand innings with 72 from 106 balls. McCullum made 44 and Grant Elliott 39 in the only other contributions of note.
In response,South Africa lost Smith for 7 in the sixth over with the total on 22. However, De Villiers (70), Hashim Amla (38) and Jacques Kallis (36) helped South Africa to achieve the target with eight overs to spare
"It was a big day for the boys," South Africa captain Graeme Smith said. "In our first game against Sri Lanka, I thought our bowlers were a little tentative in the first 15 overs. But they came back strong on the same ground, hitting their areas hard.
"I thought our overall performance was very clinical, which is pleasing ahead of our big crunch game with England on Sunday."