It was a game where neither side gave an inch, but the Blitzboks played with more composure and ensured they started the tournament on the right note.
In the week, the coaches spoke of better ball retention and defence, and the players heeded the call.
Mfundo Ndhlovu scored the opening try in the fourth minute after the Blitzboks put the ball through phases, and when Ricardo Duarttee converted, they led by 7-0.
Ireland hit back from the restart though, Matthew McDonald going over and Mark Roche adding the extras to see the teams pull level on the scoreboard, which is how it stayed until the break.
The physicality of the game started taking it's toll in the second half, but the Blitzboks stuck to their plan of using scrums, and it paid off with one minute to go when Zain Davids went over from in the corner.
The try came from a strong scrum before Donovan Don - who made his debut along with Sebastiaan Jobb - found a storming Davids on the right. There was only going to be one result, although the big Blitzbok forward had a lot of work to do to claim his 37th try for South Africa.
Duarttee added the conversion from out wide to put the Blitzboks ahead by 14-7, but Ireland fought back with vigour. However, three minutes into added time, the South Africans won a breakdown penalty to clinch the win.
In the other pool game, New Zealand beat Kenya - the Blitzboks' two opponents on Saturday - by 29-5.
Springbok Sevens 14 (7) - Tries: Mfundo Ndhlovu, Zain Davids. Conversions: Ricardo Duarttee (2).
Ireland 7 (7) - Try: Matthew McDonald. Conversion: Mark Roche.