World number 14 Ireland, who led 2-1 at half-time, scored through a Nicola Evans hat-trick in the fifth, 20th and 49th minutes while Nicola Daly nailed down a stunner in the 54th. World number 11 SA’s excellent, yet lone, goal came from Kelly Madsen in the seventh minute.
SA went into contact situations too often, not exploiting their pace and ball movement to advantage in catching the Irish defenders out.
SA must finish at least fourth in the five-team Pool B in order to make the quarter-finals on June 18 and keep their hopes alive. The top three teams qualify for the Rio 2016 Olympics with the sides ending fourth and fifth having an outside chance should other tournament results go their way.
Ireland opened the scoring against the run of play when Chloe Watkins took a quick free-hit and Evans found space to her right before steering the ball past goalkeeper Sanani Mangisa for 1-0 after five minutes.
