Even without looking at the scoreboard, it was easy to gauge the state of the game at the Shere Bangla from the din made by the home side's passionate fans. When Mushfiqur Rahim was bowled by Nuwan Kulasekara, and Bangladesh plunged to 40 for 3, the utter silence made it hard to believe there were 25,000 people watching. A hat-trick of fours from Shakib Al Hasan off Suranga Lakmal soon after was all it took for the long-suffering Bangladesh supporters to find their voice and belief again.

Once Shakib was trapped on the back foot by offspinner Sachithra Senanayake's straighter one, the volume was back to mute. A distraught Shakib slowly dragged himself off the field, turning back several times to take a look at the replays of his dismissal on the giantscreen. By the time he reached the dressing room, the players had already had their refreshments and the drinks cart was all set to return to its place beyond the boundary.

Before, that dismissal would have been enough to permanently silence them. Over the weekend, in an interview Bangladesh coach Stuart Law had said: "Shakib has carried Bangladesh for a long time. He has been the mainstay. A great bowler and a world-class allrounder, but he needs help. He can't do it every time."

Help has arrived. Tamim Iqbal and Mushfiqur Rahim have been around, but the emergence of Rajshahi allrounder Nasir Hossain over the past year has added more steel to the lower-middle order. He has built his reputation as a finisher for Abahani Limited in domestic cricket, and less than a year into his international career, he is showing signs of how comfortable he is with that role. So much so, that a local journalist asked Shakib whether Nasir could become Bangladesh's Michael Bevan.

More of a busy player than a boundary-merchant, he relies on an ice-cool temperament to keep the pressure of the roaring crowd at bay and hustles between the wickets to keep the asking rate in check. When the big hit is needed, he favours going over midwicket.

For the third time in the Asia Cup, he was called on with a chase at a critical juncture. He had faltered after taking Bangladesh close in the first game, getting some stick for a stroke perceived to be casual, but he has been spot-on in the two famous victories that followed. Even after Shakib's dismissal, the required rate was not out of hand, and Nasir poked the ball around for the singles to negate the momentum Sri Lanka had from getting the big wickets of Tamim and Shakib.

There was one could-have-gone-anywhere swipe which, luckily for him, flew over the keeper for four, and like so many other batsmen, he was troubled by Lasith Malinga's toe-seekers, but there was generally little panic as he completed a historic Bangladesh victory.

Shakib himself had been concerned whether Bangladesh could pull off a win after his exit. "When I went in after getting dismissed, Mushfiq bhai [Rahim] asked me what will happen," Shakib said. "I said 'I don't know'. But after 10-15 runs, I knew that it would happen today. Nasir's performance was vital, has been doing his job very well. Riyad bhai [Mahmudullah] was due for runs and he did so well."

Originally picked as an offspinning allrounder, Nasir made his debut at No. 8 against Zimbabwe, promptly showcasing his talent with a half-century after coming in with Bangladesh at 58 for 6. Another reviving 50 against West Indies a couple of months later was enough to earn him a promotion to No. 6 and his offspin became his secondary suit.

His other asset has been his livewire fielding, providing a major boost to the Bangladesh bowlers, never more so than in the first hour of the tournament, with a series of dives to slow down the Pakistan openers. That complements an exuberant personality that the world got a glimpse of with his over-the-top celebration on getting his first one-day wicket, against West Indies in Chittagong last year.

It is early days yet, and Nasir remains largely untested in overseas conditions, but indications are that Bangladesh have found another player who can keep the Shere Bangla buzzing even after some of the bigger names have exited.

Siddarth Ravindran is a sub-editor at ESPNcricinfo