The World Cup hosts posted a heavy first-innings total of 386-8 at Cardiff, the highest of the tournament to date, building around a century opening stand between Bairstow and Jason Roy.
The latter went on to dominate proceedings, smashing five of his side’s 14 sixes in a bruising knock of 153, but there was plenty of hard work to do before the floodgates opened.
The pair were unusually cautious against the new ball, mindful not to lose an early wicket for the third game in a row, but hit the accelerator once set.
“We had 15 off five overs, I wouldn’t exactly say we were ‘going off’ at the start,” admitted Bairstow, who took nine deliveries to get off the mark then reached a run-a-ball half-century.
“It was one of the slowest starts we’ve had but to then catch up and play in the way we did, it wasn’t a case of running down the wicket trying to slog it, they were just good cricket shots.
“That is just what we have done over a period of time. There’s nothing that’s really changed from that mentality, whether we’re facing spin or seam.
“I think we’ve played better but there’s always going to be things you try to improve on.”
Bairstow was called on to take the wicketkeeping gloves for the Bangladesh innings, with regular gloveman Jos Buttler resting after injuring his right hip while batting.
England will monitor the latter over the coming days and are likely to leave it late before deciding whether or not Buttler is fit to take on the West Indies on Friday.
Whoever ends up behind the stumps at the Rose Bowl can expect a busy shift, with Jofra Archer and Mark Wood both hitting 95mph against Bangladesh, with Ben Stokes not far behind.
“It was good to be standing a long way back. It’s great to have that theatre in the game,” added Bairstow.
“You’ve got three guys who touched 90 mph in our bowling attack and then Chris Woakes touched 87. It’s a good place to be when all the lads are firing.”
England’s unexpected setback against Pakistan had raised the stakes of this Cardiff encounter, but if there was any lingering tension, Roy’s commanding knock of 153 off 121 balls blew it away in style.
He struck three sixes in a row immediately before his exit, setting the scene for the daunting total.
As well as being a new ground record for Sophia Gardens it also represented England’s best score in the competition, eclipsing 2011’s previous high by 48.
Bangladesh never threatened to go close in reply but Shakib-al-Hasan’s classy 121 spared them a rout.
Archer topped and tailed the innings to finish with 3-29, with Wood claiming two and Stokes chipping in with three of his own.
Moeen Ali’s off-spin was certainly not missed, the all-rounder somewhat surprisingly dropped in favour of the returning Liam Plunkett, with England’s pace barrage rolling Bangladesh for 280 in the penultimate over.
After winning the toss Bangladesh predictably opened with Shakib’s left-arm spin. He was hoping to replicate the the success of Imran Tahir and Shadab Khan against England’s openers but instead burned through five chanceless overs. Roy and Bairstow were cautious at first but quickly caught up, peppering the boundary en route to a century stand inside 15 overs.
Roy was the primary aggressor, driving straight and hard and pulling with authority, but Bairstow departed for 51 when Mashrafe Mortaza found a leading edge. Roy never looked likely to do the same, hammering anything short and driving sweetly.
There was an inevitability about his hundred and a peculiarity to its arrival. A misfield in the deep nudged him over the line but his celebrations were delayed after he raced towards the non-striker’s end and barrelled into umpire Joel Wilson, who tumbled to the turf.
Having helped him to his feet, Roy had time to toast the moment. With a ninth international century in the bank he upped the ante, tearing into the spinners as he moved from 100 to 150 in 28 balls. He even threatened to join the ‘six sixes’ club, nailing Mehidy Hasan for three successive maximums to start the 35th over.
A fourth was on his mind when he swung hard at the next delivery, but this time it looped to cover.
Buttler picked up the baton with his usual flair, thrashing four more sixes, but his efforts came at a cost. Having cleared long-off with a mighty back-foot baseball swing he hobbled for the remainder of his innings and did not re-emerge.
Joe Root and Stokes missed out but a 45-run flurry from Chris Woakes and Plunkett ensured there would be no respite for a weary attack.
If England were sensing an early finish, Shakib had designs of his own. He joined Mushfiqur Rahim to put on 106 for the third wicket but by the time Shakib was yorked by Stokes the result was long settled.