Silver Ferns coach Janine Southby says she had "huge respect" for South Africa following a tight match this morning in Johannesburg.
The Silver Ferns held their nerve to beat the Proteas 51-46 in their second match of the Northern Netball Quad Series.
Read more: Netball: Silver Ferns secure win against South Africa in second Quad Series match
Southby said they had to "grind out" the win against the South African side, who held the pressure on the Ferns right until the end of the match.
"I've got huge respect for South Africa, having watched them for the last two years … they were only ever going to get better," she told Radio Sport.
"They're a threat and we know that every time we play them that we're going to have to be on top of it to win, and tonight was no different."
Read more: As it happened: Silver Ferns v South Africa
The Proteas maintained a consistent five goal deficit for most of the match, demonstrating their strength in a fast-paced final quarter.
"There was a lot of pressure from the South Africans and there were a couple of calls and we weren't sure which way it was going to go, so they [Silver Ferns] kept their head which is great," Southby said.
Southby told Radio Sport the Ferns had made "good progress" following a disappointing start to the season, ensuring there was no last-quarter meltdown as seen in their opening loss to England.
"We'd let ourselves down on Sunday in London against England, felt that we'd made some good progress around the ability to keep working and keep calm under pressure and make good decisions," she said.
"I think we can take heart from the fact that we've actually got better so far as the tour has gone on."
Read more: Quad Series: Silver Ferns prepare for much needed comeback against South Africa
Southby said although the Ferns showed a "significant shift" in their performance on court, there would still be work to do in the two days before facing the undefeated Australian Diamonds.
Shooting trio Maria Folau, Bailey Mes and Te Paea Selby-Rickit produced a low 74 per cent shooting percentage, but Southby said she was confident the girls would bounce back.
"I know that they won't be happy with that and they'll go back to the post tomorrow, but I back them to get themselves out of it," she said.
"Still lots to work on from that point of view."
The Ferns will face Australia on Sunday night at 11pm.