Two games, three runs between the teams, and one more clash to come. The T20Is have served up a buffet of belligerent boundary-hitting, as well as some nerveless death bowling and two of the closest finishes possible this side of a Super Over. Given England's recent form in white-ball deciders, you wouldn't rule out one of those being required in Centurion, either...
Having seen the tourists stutter at the last in the opening encounter, South Africa seemed set to show them how to do it in style at Kingsmead, as Rassie van der Dussen revived a flagging chase and then Dwaine Pretorius tipped the odds in Tom Curran's final over by smiting six and four from the second and third balls. A requirement of 15 off six suddenly shrank to five off three and then three off two - only for Curran to ice South Africa's hopes of claiming the series with a toe-crushing yorker to Pretorius, followed by his trademark back-of-than-hand slower ball with the pressure on.
Just as Lungi Ngidi had done a couple of nights before, Curran's chutzpah had produced a grandstand finish - and England captain Eoin Morgan described the experience as "completely invaluable", with future high-stakes encounters likely at the T20 World Cup later this year.
South Africa's disappointment was compounded by the fact van der Dussen was kept off strike for the final 10 balls of the innings, as the chase fluctuated back and forth. Quinton de Kock's 17-ball fifty had signalled they were in the mood to pull off what would have been their second-highest successful T20I chase, before wickets from Mark Wood, Ben Stokes and Chris Jordan had put England on top. Punches were met by counter combos throughout the game. England shook off their East London failure with a fast start - despite Jos Buttler again falling cheaply in the Powerplay - but were beginning to get bogged down by the time Moeen Ali arrived at the crease in the 16th over. Moeen proceeded to hit seven of the most insouciant boundaries from his next 10 balls to pep up England's chances. There was also some joy for Ben Stokes, despite a laboured start, as he made his highest T20I score of 47 not out, nearly nine years after his debut. The format is often played in fits and starts, leading to such anomalies, but with a World Cup on the horizon, this is the perfect time to build up a run of form. Both teams will be looking to grasp their opportunity again on Sunday.
(last five completed matches, most recent first)
South Africa LWWLW
In the spotlight
David Miller is now one of the senior men in South Africa's line-up and the most-experienced member of a reshaped middle order - but despite showing destructive form in the final ODI against England, he has struggled to hit his straps in T20 recently. Twice he has been part of mid-innings slowdowns, after South Africa were given good starts by de Kock and Temba Bavuma; in Durban, the stage seemed to have been set, as Miller came in at No. 3 in the eighth over, only to hole out for 21 off 16 with the asking rate beginning to rise. It seems he is still trying to shake off the effects of a poor Big Bash, having only made one score above 25 in his last 14 T20 innings. Much of the talk around England's XI has centred on the ideal batting line-up - not so much as who is in it, but where they come in. Jos Buttler is a guaranteed World Cup starter, but should his extraordinary skills be deployed against the new ball, with the field up, or at the death, when a cool temperament is prerequisite? Two innings at opener against South Africa have so far yielded 17 runs from 14 balls - and England's meltdown in East London left plenty highlighting the loss of Buttler's finishing skills. Perhaps the real issue is that, after a tough Test tour, he looks to be down on confidence. But one freewheeling innings might be all it takes for things to click back into place.
Dale Steyn was rested in Durban, a precautionary move considering his injury history, but seems likely to return at seam-friendly SuperSport Park. Bjorn Fortuin, who only bowled two overs and was then the unlucky man tasked with trying to hit three to win off his first ball in international cricket, could miss out.
South Africa (possible): 1 Quinton de Kock (capt, wk), 2 Temba Bavuma, 3 Rassie van der Dussen, 4 Jon-Jon Smuts, 5 David Miller, 6 Andile Phehlukwayo, 7 Dwaine Pretorius, 8 Beuran Hendricks, 9 Dale Steyn, 10 Tabraiz Shamsi, 11 Lungi Ngidi
Morgan has reiterated that England view Buttler as part of their strongest top three, so that may mean more time running drinks for Dawid Malan. Sam Curran and Saqib Mahmood are the fast-bowling options in the squad, though Tom Curran, Jordan and Wood all made good cases for keeping their spots. Protecting Wood from wear and tear could come into England's thinking.
England (possible): 1 Jason Roy, 2 Jos Buttler (wk), 3 Jonny Bairstow, 4 Eoin Morgan, 5 Joe Denly, 6 Ben Stokes, 7 Moeen Ali, 8 Tom Curran, 9 Chris Jordan, 10 Adil Rashid, 11 Mark Wood/Saqib Mahmood
Pitch and conditions
Among South Africa's regular T20 venues in recent years, SuperSport Park is second only to the Wanderers for high-scoring, with the ball liable to disappear at altitude. A warm afternoon in prospect should set things up nicely for the series decider.
Stats and trivia
England have only played one previous T20I in Centurion, a game in which they were captained by Alastair Cook and lost by 84 runs. The opening stand in that match of 170 between Graeme Smith and Loots Bosman was at the time the highest in T20Is. It was ended by Joe Denly, taking a wicket with his first ball in international cricket. Three of the last four encounters between these two have come down to single-figure margins, with South Africa winning two and England one.
"I wish it was a dead rubber on Sunday. But both teams have played really well. They won one or two small battles in key moments that helped them get over the line. It's great to see both teams are playing good cricket and keeping it competitive out there."
Quinton de Kock knows his team will have to go again in the final game
"Probably with two balls to go, it was South Africa's game to lose, they were in an unbelievably commanding position… I thought Tom Curran did an unbelievable job."
Eoin Morgan had praise for England's last-over hero in Durban
Alan Gardner is a deputy editor at ESPNcricinfo. @alanroderick