A blockbuster century from South Africa captain George Van Heerden propelled his side towards the Super League quarter-finals as they defeated Ireland by 153 runs in Tarouba.
The two sides started their all-important final Group B game level on points, with South Africa possessing a narrow advantage in the table thanks to their better net run-rate.
With India all but assured of their place in the Super League last eight ahead of their final game against winless Uganda, South Africa and Ireland faced a shootout for second place.
And Ireland made a dream start when Reuben Wilson removed South African opener Valentine Kitime in the first over for a duck before Liam Doherty bowled Ethan-John Cunningham (11).
At 18 for two after four overs, South Africa were wobbling but Dewald Brevis soon restored order and moved to 27 from 29 balls with two fours to take his side to 53 for two after 10 overs.
Ireland responded by taking the wicket of Gerhardus Maree (14) as Wilson struck again, yet that brought Van Heerden to the crease to form a formidable partnership with Brevis.
Brevis reached his half-century with a four off the final ball of the 22nd over and continued to find the boundary at regular intervals as Van Heerden provided support from the other end.
But just four runs short of his century, Brevis was punished for a loose cut shot off Scott MacBeth as a diving full length catch by Matthew Humphreys at gully sent him packing on 96.
While that wicket briefly halted South Africa’s momentum, Van Heerden soon took up the baton and brought up his fifty before stepping on the gas with Andile Simelane.
An explosive 25 from 12 balls from Simelane, which included three sixes and four off MacBeth in the 38th over, only added to Ireland’s troubles as South Africa moved to 207 for four.
Simelane was dismissed in the next over but Mickey Copeland chipped in with a high-octane 43 from 18 balls before Van Heerden brought up his century with a four in the 46th over.
Van Heerden eventually lost his wicket in the final ball of the innings, which was shortened to 47 overs due to an earlier rain delay, with South Africa finishing on 315 for seven.
Ireland’s response could not have got off to a worse possible start as Liam Doherty was caught by Maree off the bowling of Matthew Boast for a golden duck in the first ball of the innings.
Nathan McGuire steadied the ship with 42 from 33 balls before Simelane took his wicket, with Joshua Cox and Ireland captain Tim Tector both falling cheaply to Boast.
Philippus Roux (33) provided some resistance along with Humphreys (38) but a lack of support meant Ireland were always fighting an uphill battle and they were eventually all out for 158.
Boast was the star of the bowlers for the young Proteas with three for 26 while Liam Alder also took three for 20, with Asakhe Tsaka and Simelane contributing two each.