The tourists take an unassailable, 3-0 lead in the four-match ODI series.
Wolvaardt’s 105 came off 125 deliveries (14 fours) and Chetty’s score off 130, including nine fours.
The pair put on a 192-run opening stand to lead South Africa to 260/6 after electing to bat first.
Mignon du Preez added 22 (13) and Lara Goodall 19 (20) to round off the day’s most notable batting contributions.
Ireland’s batting reply was snuffed out by a ferocious Luus, who was taking no prisoners. Her five wickets came off 36 runs with good assistance from Ayabonga Khaka who chipped in with 2/31.
The visitors will look to end the series on a high and complete a whitewash when they meet in the last match on Thursday.
