Ill-disciplined Ireland were shown five cards as South Africa produced a typically power-packed performance to win a chaotic, bruising autumn Test - their first victory in Dublin since 2012.
Having bounced back from an opening November loss to the All Blacks, Ireland had hoped to claim a statement win over the world champions to end 2025 on a high.
But coach Andy Farrell was forced to rip up his gameplan on a hectic and deeply frustrating evening which yielded a red card for James Ryan and yellows for Sam Prendergast, Jack Crowley, Andrew Porter and Paddy McCarthy.
Damian Willemse gave the tourists a dream start with a fourth-minute try, before Ryan's yellow for a high hit on Malcolm Marx in the build-up to Tadhg Beirne's disallowed try.
After the card was upgraded to a 20-minute red, Cobus Reinach extended the Springboks' lead with Prendergast also sin-binned, before Dan Sheehan crossed for Ireland.
In a devastating end to the half for the Irish, though, Crowley and Porter were also shown yellows, while South Africa were awarded a penalty try to take an imposing 19-7 lead at the break.
Ireland could only muster six points in the second period through two Prendergast penalties, with Sacha Feinberg-Mngomezulu's superb individual try ensuring a first win on Irish soil for the Springboks in four attempts.
