Cool-headed Shoaib Malik shows how he fits into this Pakistan side

As Mohammad Hafeez trudged off in Sharjah after a cameo of 31 off 19 balls, Pakistan waited intently. With five overs to go and a solid platform built, surely this was the time to send in Asif Ali, the star of their wins against New Zealand and Afghanistan, for a late blitz ahead of the knockout stages?

To the crowd's disappointment, in walked Shoaib Malik: short sleeves, sweatband, durag and all. Malik was not meant to be in this side: only two months ago, he was in the midst of one of the worst runs of form a specialist batter has ever endured at a T20 league, averaging 7.44 in 10 innings for Guyana Amazon Warriors, and he missed out on selection in the initial squad.

When he was confirmed as a replacement for the injured Sohaib Maqsood last month, the usual clichés about experience and a big-game mentality were trotted out but they could hardly have been further from the truth. In fact, Malik had not scored a half-century in an ICC event since the 2009 Champions Trophy; in leapfrogging the reserves, Malik seemed to have been picked on reputation rather than reason.

But in this tournament, Pakistan can do no wrong. Their win against Scotland ensured their progress to Thursday's semi-final against Australia as group winners and maintained their status as the only unbeaten team in the competition. Every decision they have made appears to be paying off, and any lingering doubts about their credentials cast aside.

So it was no surprise that when Malik sauntered off 25 minutes later, he did so having ended that 12-year run without a fifty at a world tournament and with the crowd chanting his name, rather than Asif's. Naturally, a low-pressure slog against Scotland's spinners offered limited practice for closing out a game against Mitchell Starc and Josh Hazlewood next week, but it added to the sense that everything is clicking for Pakistan.

By this point in his career, Malik's preference for spin bowling should be clear. In T20 cricket this year, he has been dismissed every 18.2 balls against seamers compared to 39.6 against spin; his role in Pakistan's middle order is to target the final overs of spin before Asif takes over at the death against the seamers. "It's a no-brainer: you just don't bowl a spinner in front of Shoaib Malik," Shan Masood said on Cricday's T20 Time Out.

It was a surprise decision, then, for Kyle Coetzer to leave Brad Wheal's final two overs unbowled, meaning Malik faced only four balls of pace across five overs. He got going by clobbering Mark Watt - Scotland's best bowler of the competition - over long-off, using his long levers and letting his bottom hand take over to clear George Munsey on the rope.

After blasting Saafyan Sharif over midwicket and then long-on as he missed his yorkers, twice straying into the slot, Malik ruined Chris Greaves' figures in the final over, hitting the final four balls of the innings for three sixes and a four to take Pakistan to 189, an unassailable total even on a pitch offering Sharjah's new trademark: low bounce from a good length.

Greaves was a bold choice for the final over, despite his figures of 2 for 17 after his first three: he had enjoyed several lucky escapes when drag-downs were pulled to boundary-riders on the bounce, and Malik was always one step ahead, setting himself deep in his crease when he dropped short and skipping down the track when he pitched full. "We decided it was tougher to take down the spinners on that surface and tried to keep pace off the ball," Coetzer explained. "Greavo had bowled excellently… he got two balls into the over but Shoaib used his skill and his ability to range-hit is pretty spectacular, to be fair."

Malik raised his bat nonchalantly to the crowd on his way off, as though this was nothing new for him; in fact, he had equalled KL Rahul for the fastest fifty of this tournament, and went clear of Umar Akmal for the fastest fifty by a Pakistan batter in men's T20Is. Of course, it came against an associate nation who had been on the road for six weeks and were already out, but his death-hitting can only bode well.

While Malik's dreadful CPL form suggested he was a poor pick, his record in the UAE this year - averaging 36.14 with a strike rate of 162.17 in the second half of the PSL, and hitting 225 runs off 151 balls across six National T20 Cup innings - reflected his skill on slow, low pitches. "When Pakistan initially chose their side, it was more based on boundary-hitting, six-hitting," Masood said. "Having watched the IPL in the UAE and the National T20, they figured out that they might need some cool heads out there in the middle."

Almost everything has gone as hoped for Pakistan in the group stages, with Fakhar Zaman and Hasan Ali the only two players who could reasonably be accused of underperforming. In all likelihood, both with keep their places for the semi-final: Fakhar breaks up a run of right-handers in the middle order and will be tasked with taking on Adam Zampa and - if he plays - Ashton Agar, while the only feasible replacement for Hasan is the 20-year-old Mohammad Wasim.

Pakistan have defied their reputation as a volatile, inconsistent side in this tournament, extending their winning streak in their home away from home to 16 games. They are fighting history in their bid to win this competition - no side has ever gone unbeaten throughout a men's T20 World Cup - but their ruthless group stage performance suggests that it is a statistical quirk they could overcome.