South Africa captain Faf du Plessis was a relieved man after the Proteas edged out England by three wickets in a final-ball thriller in Friday's first Twenty20.
Having restricted England to 134-8 at Newlands, South Africa toiled in their chase and needed 15 from Reece Topley's final over.
As in the fourth one-day international a week ago, Chris Morris proved the hero, thumping a four and a six to leave the Proteas needing two off the last ball for victory.
Morris drilled the delivery down to Joe Root at long-off and Topley failed to cleanly gather the throw as Kyle Abbott dived home at the non-striker's end to put South Africa 1-0 up in the two-match series.
"That's a massive get out of jail card," said Du Plessis in the post-match presentation. "But you still need to win games when you're not in a position to win it.
"Both teams didn't play at their best. It wasn't a normal T20 wicket but there's a smile on my face because we've won the first game.
"We didn't start well but brought it back nicely. We messed it up a little bit but Morry [Morris] had a nice little cameo and the million-dollar man saved us.
"We'll learn from these things. We'll try and improve and be better for the next one."
Losing skipper Eoin Morgan, meanwhile, had praise for his bowlers following a below-par batting effort.
"After a poor batting display our bowlers pulled it out the bag," he said. "Ben Stokes and Chris Jordan really did get as much as they could out of the pitch and put South Africa under pressure.
"That's one of the huge positives. We probably should have won and didn't deserve to with a poor batting display."