South Africa 211 for 5 (Hendricks 74, Markram 56, Delany 2-31) beat Ireland 190 for 9 (Tucker 78, Dockrell 43, Maharaj 2-29) by 21 runs
Bristol: Half-centuries from Reeza Hendricks and Aiden Markram helped South Africa to a 21-run win in the first of two Twenty20 internationals against Ireland.
Hendricks made 74 from 53 balls for his fourth successive Twenty20 fifty, and Markram 56 off just 27 deliveries, to help the Proteas reach 211-5.
Despite a fine batting display from Lorcan Tucker (78), Ireland fell well short of their target on 190-9.
The sides will meet again at Bristol on Friday.
Hendricks, who starred in his country's recent series win over England, continued his fine form during the day-night match.
The opener shared a third-wicket partnership of 112 with Markram, who smashed five sixes during his innings.
Spin bowler Gareth Delany claimed the wickets of Hendricks and Markram from successive balls in the 16th over - Markram being caught at deep square leg before Hendricks holed out to point - but Ireland were unable to reach their total despite a spirited reply.
Tucker, batting at number three, managed seven fours and five sixes in an impressive knock of 78 from 38 deliveries, while 43 from George Dockrell further boosted the Irish cause.
Yet hope of a famous win was effectively extinguished when the pair fell in the space of three balls to Tabraiz Shamsi and Dwaine Pretorius respectively.
A target of 37 from the final two overs never looked like being achieved, with Proteas' 'death-bowling' specialist Wayne Parnell proving his worth despite being hit for six off the last ball off the innings by tailender Barry McCarthy as Ireland finished on 190-9.
Left-arm paceman Parnell returned figures of 2-36, having removed opener Andy Balbirnie, with stand-in Proteas captain Keshav Maharaj taking 2-29 with his left-arm spin and leg-spinner Tabraiz Shamsi 2-37.
South Africa suffered a setback before the match started, with captain David Miller ruled out by a back spasm, with fellow batsman Heinrich Klaasen taking his place in the XI.
Proteas fast bowler Kagiso Rabada had already been sidelined from both matches.