A lapse of concentration in the opening five minutes of the second half saw the Irish girls profit through an Aine ‘O Gorman half volley from inside the penalty area to make the score 1-0.
Banyana dominated the contest in the first-half, struck the crossbar three times in the second half, but unluckily failed to score against the opponents who came into the match buoyed by a 5-1 opening day drubbing of Northern Ireland also in Group C.
Playing with the advantage of the wind in the first-half, Ireland put Banyana on the back foot but they weathered the pressure.
Refiloe Jane and Amanda Dlamini produced a far better display in the middle of the park to stifle the Irish but it was upfront where Banyana's attack looked jaded.
Jane, in particular, played superbly as the protective shield for the back four. Jermaine Seoposenwe was sent through by a defence-splitting pass from Jane but saw her shot saved by Ireland goalkeeper Emma Byrne midway through the first-half.
Substitute Noko Matlou and fellow striker Nomathemba Ntsibande, came close to scoring on three occasions in the second half but first Matlou's header agonizingly shaved the upright. Moments later, Ntsibande struck the upright with a fierce low shot while the Ireland keeper Byrne dived low to save one of Matlou's other attempts towards the end of the match.
Arguably the best player on the park for Banyana was winger Mary Ntsweng. She thought she had scored with a long-range shot but watched in disbelief as the shot cannoned off the crossbar following sustained pressure by Banyana who searched without luck for the equaliser.
Despite conceding early on in the second half, South Africa keeper Andile Dlamini performed well on the few occasions she faced challenging situations.