The win was the second straight and third in four games for the Devils following a six-game losing streak that dropped them close to the eighth-place cutoff for the playoffs.
Kieswetter sliced straight to third man when on seven but survived because Morne Morkel was no-balled for over-stepping and South Africa's frustration was compounded as an edge by Pietersen edge bisected Jacques Kallis and keeper Mark Boucher, leaving the two veterans looking at each other and the ball flying to the boundary.