Stuart Broad's anticipated one-day international return was confirmed by England at the toss as South Africa opted to bowl first at the Wanderers.
Broad was back, for his first ODI in 11 months since England's embarrassing World Cup campaign last winter - and in too was his fellow seamer Chris Woakes, as England freshened up the attack which could not stop the hosts chasing 318 for eight at Centurion three days ago.
Chris Jordan and David Willey were the men to make way.
England, who can clinch the series here with victory for an unassailable 3-1 lead with one more to play, must set a total again at a ground famous for its high scores down the years - after AB de Villiers chose to bowl on a sunny afternoon.
South Africa rested pace linchpin Morne Morkel and brought in Chris Morris.