Just when even their most loyal supporters were beginning to lose faith, just as the cornered tigers had started to look like tamed kittens, long after the cliché about them being mercurial had become not so much a description, as a desperate expression of hope, Pakistan go and do something like this.
You didn't think they had become predictable, did you?
Victory here - albeit in another rain-ravaged match in a tournament that is in danger of drowning - not only revives their hopes of qualifying for the semi-finals, but suggests things are not quite as bad as they seemed against India on Sunday night.
Nobody should think that all Pakistan's issues are resolved. They still lack big-hitting batsmen; they still have a long tail; they still need to find a way to produce more batsmen and they probably benefited from the shortened nature of the match. For some, this performance will just render Sunday's drubbing all the more frustrating. It is hard to avoid the conclusion that the magnitude of that occasion simply rattled them.
But this victory did come against the world's No.1 ranked ODI team. And it did provide a reminder that, for all their frailty with the bat, they have a potent bowling attack that, given just a bit of support from its fielders, can win them games.
There were several factors behind Pakistan's improvement, not least the selection, the fielding and an oddly-tentative performance from South Africa who, it has to be said, played a large part in their own downfall. This was almost a stereotypical performance from both teams, with one unpredictably brilliant and the other unpredictably wilting under pressure. It was all so very Pakistan. And all so very South Africa.
But the key ingredient was reverse swing. In a tournament that has been characterised by the impotence of bowlers, Pakistan at last found a way to make the ball move laterally. It was only an inch or two; it was only for a while. But that reverse swing gave Pakistan a weapon and they have bowlers who knew how to use it.
The swing was probably created by the surface. With poor weather convincing the groundsman to abandon plans to use a new pitch - he was concerned it would start damp, the ball would make indentations in it and it would then be unsuitable for usage in Saturday's match between England and Australia - it was decided, instead, to revert to the surface used in the first two matches of this tournament at Edgbaston.
That meant it was drier and a bit more abrasive than previous matches. And with Pakistan introducing spin into the attack early, allowing them to scuff up one side of the balls perfectly legally, the Pakistan seamers were able to return as early as the 23rd over and Hasan Ali struck in the 29th - meaning that ball was only 15 overs old - and attack at a time batsmen have been tending to dominate in this tournament.
Hasan struck with successive deliveries in that over. Angling the ball into JP Duminy from around the wicket, Hasan persuaded it to leave the left-handed batsman just a touch but enough to draw the edge and reward Pakistan for persisting with a slip when they saw the first signs of movement. Wayne Parnell fell in almost identical fashion to the next delivery, only he missed the ball entirely and lost his off stump as a consequence.
By then, though, Pakistan's spinners had already claimed three wickets out of six. After Junaid Khan, far more accurate than the injured Wahab Riaz, and Mohammad Amir conceded only three fours in the first Powerplay, the spinners built pressure. While there was little sign of any turn, the pitch was slow enough to render stroke-making a little more difficult than has been the case so far this tournament and, with Imad Wasim and Mohammad Hafeez bowling admirably straight, any mistake by South Africa's jittery batsmen was punished.
To apply any pressure, though, it was essential Pakistan produced a better display in the field. They were unrecognisable from the rabble we saw on Sunday. From the first moments, throws buzzed back towards the keeper in the field. Fielders threw themselves around in an attempt to cut-off the ball - Hasan launched himself full length to save a run in the opening minutes - and all the trepidation of Sunday was replaced with commitment, belief and desire.
There was still a ghost from the past. Ahmed Shehzad, dropped after his apparently ambivalent performance in the first match, was briefly pressed into use as a substitute fielder and promptly conceded a run after letting the ball bobble through his hands at cover. On Sunday, such errors hardly stuck out as they were the norm; here it was an infuriating aberration.
Shehzad's replacement also impressed with the bat on his ODI debut. While it would be an exaggeration to say Fakhar Zaman was completely convincing - he took two crushing blows off bouncers, one to the head and another to the shoulder - he was wonderfully committed to the cause. By the time he had faced 11 deliveries, he had struck more fours (three) than anyone in the South Africa side and by the time he had faced 18, he had struck three more. It was exactly the bold start a nervous Pakistan side required and in stark contrast to Shehzad's cagey performance of Sunday. It allowed them to soak up later pressure - at one stage they faced three maidens in succession and scored only four runs in five overs - and ensure they were still ahead of the rate when the rain came.
But the improvement on Sunday's performance was best summed-up by Hasan's fielding. Having failed to hold on to a chance off Yuvraj Singh at long-off - and failing to reach another possible chance - he took two in a similar position here with the second, to dismiss Kagiso Rabada, an excellent running effort.
It wasn't, by any means, a perfect performance. But it was a decent step in the right direction.