The hot and humid conditions made handling difficult, but the South African pack laid the foundation for a solid win against the 2022 Six Nations and Grand Slam champions, outscoring their opponents by five tries to three, with the final Irish try coming after the hooter had sounded.
Cameron Hanekom, Reinhardt Ludwig, Tiaan Lange, Corne Rahl and Lukhanyo Vokozela crossed for the tries, while Sacha Mngomezulu added four conversions.
With England beating France earlier on the day, the SA U20s now lead Pool A with a full-house of 10 points, followed by the English and French on five points each, while the Irish are yet to open their account.
Nhleko mentioned afterwards that he was happy with the win, considering that the South African U20s had made six changes to their starting pack.
“We knew that Ireland would be hurting (after losing to France) and the way they came back in the second half put us under pressure,” said Nhleko, who added his side did well to close the game out.
“It’s part of the learnings for our group and the conditions were not easy because of the heat and humidity, which made for a slippery ball.”
Following South Africa's impressive start, it was the Irish who grew in confidence in the second half to score three times while limiting the Junior Boks to just one try.
“They were unbeaten in the U20 Six Nations and showed their pedigree in the second half,” said Nhleko.
“We wanted to stop them from getting quick ball at the breakdown and from gaining momentum, and I thought we were successful in that.
“But there were times when we left them off the hook and put ourselves under pressure.”
The Junior Boks tackle France next week Tuesday in their third outing, with the match set to kick off at 17h00.