Spinner Tabraiz Shamsi took four wickets as South Africa comfortably beat Ireland by 33 runs in the first game of a three-match Twenty20 series in Dublin on Monday.
Aiden Markram top-scored for the visitors with 39 and David Miller chipped in with 28 as South Africa reached 165-7 in their 20 overs.
Seven of the top eight batsmen reached double figures after the tourists were asked to bat although nobody went on to make a big score.
Ireland slumped to 46-5 in reply, with Harry Tector (36) offering resistance but wickets tumbled regularly and the hosts could only muster 132-9.
Shamsi, the top-ranked bowler in T20 cricket, ended up with figures of 4-27 off his four overs.
The teams meet in Belfast on Thursday and again on Saturday.
The recent one-day international series between the sides finished 1-1.
Brief scores
South Africa 165-7, 20 overs (A Markram 39, D Miller 28, R van der Dussen 25; M Adair 3-39)
Ireland 132-9, 20 overs (H Tector 36, A Balbirnie 22; T Shamsi 4-27)