While the Proteas lost out in the first match, losing by one run according to the Duckworth-Lewis method in a game affected by rain, they won the second Standard Bank Pro20 match at Supersport Park on Sunday in emphatic fashion, beating England by 84 runs to level the series 1-all.
Chasing 242 to win, England made 157 for eight.
Smith and his opening partner Loots Bosman got the match off to a brilliant start, with a world record partnership of 170 - surpassing the previous record held by Chris Gayle and Devon Smith of the West Indies.
Alastair Cook, standing in for the injured Twenty20 (T20) captain Paul Collingwood, tried all the available bowlers, but the South Africans flayed them all.
They really climbed into Sajid Mahmood, whose first over went for 21 runs, but there were few English bowlers who did not come in for punishment, and Smith and Bosman smashed 13 fours and 15 boundaries between them. They each reached their half-centuries off 25 balls, equalling the South African record set by AB de Villiers against Scotland in the World Cup earlier this year.
It took part-timer Joe Denly to break the partnership with his first delivery in international cricket, when Smith was caught at long-on by Mahmood for 88.
South Africa began losing wickets at frequent intervals, but Smith and Bosman had done their job to perfection, and runs continued to pile up.
Bosman was finally out for 94, caught by Denly off Luke Wright.
South Africa finished on 241 for six - the second highest score in international Twenty20 cricket.
Chasing a target of 242 to win was always going to be a big ask, and England were never able to keep up with the run rate, which continued to soar. Denly fell in the fourth over, bowled by Yusuf Abdulla for 14, and Cook was next to go, caught at midwicket by Roelof van der Merwe off Albie Morkel for 26.
When Kevin Pietersen joined Jonathan Trott in the middle, there were 13 South African-born players on the field, as well as the two umpires. Trott and Pietersen shared a third wicket stand of 52 off 31 balls, which ended when Trott hit a Morkel delivery high in the air - wicketkeeper Heino Kuhn got into position, steadied himself and took his first international catch to dismiss Trott for 51 off 40 balls.
Pietersen attempted his "switch-hit" against Van der Merwe's spin, only to see his wicket shattered, and he went back to the dug-out on 29.
Dale Steyn took two wickets in his final over, to dismiss Eoin Morgan and Luke Wright, Ryan McLaren sent Tim Bresnan back and Kallis ran Adil Rashid out in the final over. England finished their 20 overs on 157 for eight.
Although the series was shared one-all, there is no doubt that Graeme Smith will be happier than Andrew Strauss as the two teams start their preparations for the first one-day international at the Wanderers in Johannesburg on Friday.