South Africa came into the game fresh from beating world champions New Zealand but were overwhelmed in the second half by an Irish side without seven of the team that clinched the Six Nations trophy in France last March.
Tries from flanker Rhys Ruddock and wing Tommy Bowe together with a perfect kicking display from flyhalf Jonathan Sexton handed the Springboks their first loss to European opposition since defeat in Scotland four years ago.
“It wasn’t perfect (but) heading towards the World Cup, towards the Six Nations, it’s important to beat this sort of team to boost confidence,” Sexton said in a pitchside interview.
Ireland, carrying an injury list that included British and Irish Lions forwards Sean O’Brien and Cian Healy, started well, impressively standing up to the big South African pack to allow Sexton to kick them into the lead on nine minutes.
They had to weather constant but ineffective Springbok pressure to hold on to the lead as the visitors came up against tough Irish defence but were also guilty of poor execution as the clinical Sexton punished them by slotting over a trickier penalty to extend the advantage.
His opposite number Handre Pollard, who missed an early shot at goal, opted to kick a couple of far easier penalties to the corner but again the Springboks knocked on at the crucial moment.
The young flyhalf could not say no when presented with a penalty right in front of the posts to cut the deficit in half at the break, but three points was a poor return for 30 minutes of concerted pressure.
Ireland started the second half in the same vein and after a clever kick through from centre Robbie Henshaw – part of a new midfield partnership with debutant Jared Payne – they had a lineout metres out and the game’s first try.
The South Africa defence evaporated as Ruddock, a last- minute replacement for the ill Chris Henry, peeled away to dart clear over the line for his first international try which Sexton converted from close to the touchline.
Pollard again refused a very kickable penalty opportunity after 55 minutes but this time his forwards, reinforced by early replacements, delivered as Marcell Coetzee emerged with the ball after the pack crashed over.
Pollard’s conversion made it a three-point game again but Sexton’s kicking masterclass continued as he put another difficult penalty right between the posts.
Ireland’s organisation and discipline hardened as South Africa’s disappeared when replacement hooker Adriaan Strauss was sin-binned 14 minutes from time for taking Rob Kearney in the air, handing Ireland the opportunity to close the game out.
The hosts went for the jugular and while unlucky initially not to add a second try, Sexton made it five successful kicks from five to put more than a converted try between the teams.
Ireland swelled with confidence and Bowe, who missed the entire Six Nations campaign through injury, put them out of sight when he collected a superbly-weighted kick from scrumhalf Conor Murray to dive over for his 27th international try.
Replacement Ian Madigan took over where man-of-the-match Sexton left off with another successful long kick at goal before JP Pietersen grabbed a last-minute consolation score but his side were already well beaten.
(Additional reporting by Conor Humphries, editing by Ed Osmond)