India had the key in the lock with South Africa 20 for 3 after four overs and brought on Varun Chakravarthy to turn it and shut them out of the contest.
In theory, it was the smartest move they could have made, given Varun's stellar record against South Africa of 23 wickets in 35 overs across nine T20Is at an average of 12.91. What happened was that David Miller had other plans.
He had to do three things: make sure he got South Africa out of trouble; make sure he scored at a quick enough rate to be able to lay a foundation for a competitive total; make sure he was providing enough guidance to Dewald Brevis, who, despite being the X-factor, is playing in his first T20 World Cup.
At first, it looked like a tough task. Miller was beaten and then edged one past slip for four. But then Varun bowled one in the slot, Miller saw the chance to counterpunch and took it. He lofted the ball over mid-off for a confident second boundary and got South Africa rolling.
From then on, Miller's approach was that if it was there to be hit, he was going to hit it. When Arshdeep Singh went too short, he smeared it leg side for four. When Washington Sundar floated it in slowly, Miller backed away from his stumps to give himself room, and time, to carve it through long-off. But it was the takedown of Varun in his second over that suggested South Africa were getting on top of India, and it involved Brevis too.
With the ball in his arc, Miller hit Varun for a 95-metre six over long-on. Then Brevis created space for himself as he moved outside leg stump and sliced Varun past point and then finally, the shot we had been waiting for: the no-look six, which was actually a half-look six. Brevis sent Varun back over his head to bring up the fifty partnership of 29 balls and it was clear momentum had shifted and South Africa's approach to playing Varun had changed.
Miller confirmed it at the post-match press conference: "He's a world-class bowler and he has had huge success in all the different formats that he's played and in the past we've been quite tentative. It was about really making sure that we were on it. If he bowled a bad ball we've got to put it away. It was about showing a little bit more intent. It also wasn't spitting too much tonight, so you could trust the line. Once we felt that, we felt we've got to take him down because he is a threat to every team that he plays against so it was definitely something that we spoke about."
Overall, Varun conceded 47 runs in his four overs; the last time he had played South Africa was also in Ahmedabad, and he had conceded 53. On that occasion, Varun took four wickets in a game where over 400 runs were scored. This time, he only got one and it was Miller's as he tried to accelerate in the 16th over, having already top-scored and put South Africa in a relatively strong position.
He would have been disappointed not to see them through the 20 overs but because South Africa bat deep, his bigger job was simply to take them out of choppy waters and set them on course.
"In these situations, when you are 20 for 3, it's just about making sure that you're really in good positions and not necessarily loose. That's just how I approach it," he said. "It's about making sure that my intent is really good. You have to be able to put the bad balls away and we did that really well then just trying to keep that momentum going. We knew that we had [Tristan] Stubbs and [Marco] Jansen and [Corbin] Bosch in the shed so that allowed us to keep going."
Stubbs lived up to his finisher's label when he ended the innings with two sixes to end on 44 not out off 24 balls and complement Brevis' knock of 45 off 29. With Miller sandwiched between the two youngsters, South Africa have as strong a middle order as they ever have, which combines youth and experience, who they will back against most opposition.
For Miller, it's almost a full-circle opportunity to pass on what he knows to those who will follow. When he made his debut, 16 years ago, albeit that T20 was a slightly less explosive game, Miller was talked about as the prodigious young talent who could clear the rope with ease and the hope was that he would be given the freedom to keep playing that way. Age and experience have given him more responsibility as time has gone on, but he still plays some of South Africa's most important knocks and has some sage advice to pass on too.
"I've been playing the game for a while now and it's about making sure that when there's high-pressure moments in front of a big audience like tonight, I really stick to simple things and basics and do that really well," he said. "My intent was up, I was making sure that I had limited movements [at the crease], controlling my breathing, running hard, all those simple things that are cliched, but in the heat of battle, those are the things that I've touched on. This game is a game of risks and you are going to fail as a cricketer so it's about making sure that you play to your terms."
And that's how South Africa stopped India from closing the door on them and barged through instead.