An English middle order with almost 25,000 Test runs between them managed just 25 in Rawalpindi. It took the mischievous, moustachioed Sajid Khan just over a session to dismiss all four of Ollie Pope, Joe Root, Harry Brook and Ben Stokes: he celebrated each by he patted his thigh and pointed to the sky, and England's rookie soon had the number 1.7 in his sights.

Instead, Smith seized the right moment to brilliantly defeat Sajid, demonstrating his ability to effortlessly glide through the gears that had earned him his call-up. He defended resolutely against Noman Ali, the left-arm spinner who dismissed him twice in the second Test, but eliminated Sajid in an attack of five fours and four sixes, confirming his rare combination of talent and temperament.

England looked spooked by the pitch during their collapse in the halfway line, with sharp turns offered from the outset and several balls sent low through the goal. They tried unsuccessfully to get out of the jam, and it was only Smith's calm mind that realized the slowness of the turn rewarded playing straight, especially early in his innings.

“If Ben Duckett says it’s hard to sweep, then it’s probably close to impossible,” Smith said. “I took that into account and definitely tried to word it as much as possible – even though it can be a pretty good run-scoring shot out here. It was just a matter of being a little more selective.”

He managed nine runs from his first 32 balls and slowly built a partnership with his Surrey teammate Gus Atkinson before sensing his chance to put Sajid under pressure. Twice in succession he hopped across the pitch and dragged it across midwicket: first across the ground, then over the rope, despite an athletic attempt by Saim Ayub to parry the ball back into play.

This was Smith's opportunity. “I felt like he changed his plans a little bit and started to go a little further,” he said. “It felt very similar with him playing on one side and the left-arm spinner on the other side. We thought, 'How can we try to change the dynamic of the game and maybe dictate the conditions a little bit when we go to the far corner?' of the innings?'”

Smith's slog sweeps and leg-side pick-ups occasionally earned him dirty looks from the animated Sajid, but eventually forced Shan Masood into a bowling change. For the first time since they scored 823 in the first Test, England's batters were in contention: by the time the seventh wicket stand passed the 100 mark, they had emphatically regained superiority.

Atkinson fell soon after and Smith upped the ante even further by using his feet and firing Zahid Mahmood's legspin for two sixes in a row in three balls. He had to struggle after failing a slog sweep straight into the air to fall to 89, but his innings had not only changed the day but possibly the series too.

This was the scenario England had in mind when they picked Smith at the expense of Ben Foakes, who had scored under 40 in India. “We think he can handle the pressure… but his challenge is to bring the other side to his game,” said Rob Key, England's chief executive. “We want someone who can play both types of shots and we believe Jamie Smith can do that.”

While Smith looked so good during his home summer in England, playing abroad is a completely different matter. It's not just about dealing with new conditions, but also the intensity of the environment: Ben Stokes described this tour as “Groundhog Day” as England's presidential-level security confines them to their hotels outside of training and games.

Smith has never set foot in Pakistan before and his first experience as a wicketkeeper abroad in a Test match challenged both his stamina and his ability. In Pakistan's first innings in Multan, he suffered a leg-side strangle in the fourth over and then missed his only other chance – a stomp to Joe Root – in the blazing sun some 143 overs later.

The second Test was even more difficult: “You're not going to get tougher conditions to keep wicket,” said Brendon McCullum, a man who knew. In his estimation, Smith was as close to the Mariners' stumps as he has been since the Under-11s and missed a costly chance when Salman Agha was on four. He then scored 63, putting the game beyond England's reach.

But Smith impressed England with his mentality in his first appearance in the England team: assistant coach Paul Collingwood says he “never seems to change his behavior no matter what happens”. At 24, that's an impressive trait – Smith believes he developed playing with older teammates as he moved up early in Surrey's age group system.

He quickly becomes England's man for the crisis. “I don’t mind situations like this: there’s not much to lose and everything seems to be gained,” he said. “I want to be someone who can do it in all conditions – not just at home – and also against spin and seam. So it’s pretty gratifying to come out here and put in this performance.”

Smith will be named in the England squad that tours New Zealand at the end of this series, but will be unavailable for at least one Test – and possibly all three – due to paternity leave; his partner is expecting in mid-December. He is yet to make a “firm decision” on how many games he will miss – but from this evidence England will clearly miss him.