England have taken an unassailable 2-0 series lead over the Proteas after a four-wicket victory in Paarl on Sunday.
The visitors won the toss and elected to bowl first in the second T2oI with the Proteas opting for Reeza Hendricks in place of Pite van Biljon.
But a slow start saw the Proteas bat through their innings on the back foot with Quinton de Kock top scoring with an 18-ball 30 as the home team posted 146-6 in their 2o overs.
Tabraiz Shamsi, however, gave the Proteas a sniff with three wickets in his allotment of four overs as the England top order slumped to 83-4 when the dangerous Ben Stokes departed.
Dawid Malan, though, struck a beautiful half-century and was well compliment by his captain Eoin Morgan as England got over the line in the final over of the match.
The two teams will meet again in Cape Town on Tuesday for the final T20I.