South Africa lost their opening tour match against India A by eight wickets on a batting paradise in Delhi on Tuesday.
Faf du Plessis chose to bat first and the top order, apart from Quinton de Kock who was run out for two, all got runs.
AB de Villiers (37) and Du Plessis (42) shared a 87-run partnership for the second wicket. Duminy was in fine form, coming in at No 4 and hitting 68 off just 32 balls to help propel South Africa to 189-3 in 20 overs.
Du Plessis retired hurt to rest his knee. He has just come back from a knee injury that kept him on the sidelines for eight weeks and South Africa can ill afford to lose their T20 captain again.
Manan Vohra (56) and Mayank Agarwal (87) got off to a flying start, batting at 10 runs an over and sharing an opening stand of 119 before Vohra fell to Duminy, caught by Farhaan Behardien.
South Africa used seven bowlers, but all of them struggled and only Chris Morris managed to keep his economy rate below seven.
Duminy, Eddie Leie, Kyle Abbott and Kagiso Rabada all went for 10 an over or more as India A reached 193-2 in 19.4 overs to win the game.
South Africa play India in the first of three T20I’s on Friday.