The touring New Zealanders slumped to an 85-run defeat in their final warm-up match before facing South Africa in two Test matches.
They went down to South Africa A on the final day of a four-day match at Sedgars Park Sunday.
The Black Caps' fate was effectively sealed when Ross Taylor was out for 86 in the fifth over of the day, caught at gully by South Africa A captain Boeta Dippenaar off fast bowler Friedel de Wet.
Taylor and captain Daniel Vettori resumed with their side on 230 for six, needing another 128 to win.
With Taylor gone after after a 124-ball innings, which included 14 fours and a six, it was a matter of time for the bowlers to work their way through the tail.
De Wet, who took six for 50 in the first innings, followed up with three second innings wickets for match figures of nine for 126.
The New Zealanders go into the first Test at the Wanderers in Johannesburg with a win and a loss in their two first-class matches.
Of most concern will be the form of their top-order batsmen, with only opener Craig Cumming, Taylor and wicketkeeper Brendon McCullum having made half-centuries. Skipper Vettori, who was last out for 30 Sunday, hit two half-centuries as a lower order batsman.