In securing victory over Namibia in a rain-shortened thrash, England had done all they could do. It was then back to the team hotel, bolstered by a 41-run win, to discover whether Australia could offer them safe passage into the Super Eight phase of this men’s T20 World Cup by beating Scotland in St Lucia.

It had been a maddening afternoon in North Sound, rain showers having pushed the 1pm start back some three hours and leaving just enough time for what, with one further mid-innings burst, became a 10-over per side contest. But after all that waiting around, the ground staff having performed cricket’s version of the Cha Cha Slide, Jos Buttler’s team hauled themselves level with Scotland’s five points. More importantly, they had nudged them out of second place on net run-rate.

Related: Namibia v England: T20 Cricket World Cup – live

“It is a big relief and it was a stressful day when the rain was coming down,” said Buttler, his side having earlier posted 122 for five before defending an adjusted target of 126 from 10 overs. Asked if he would be making a rare exception and supporting Australia later on, the England captain replied: “Absolutely.”

This was the only remaining question, with Richie Berrington’s gutsy Scotland team still able to leapfrog them once more with what would be a shock victory. At the end of a day that had seen English nerves seriously tested – the possibility of a terminal washout felt on the cards at one point as the dark clouds lingered overhead – nothing felt certain when they boarded the team bus.

Namibia, who finished on 84 for three, also had their chances to make all this irrelevant. Opting to bowl first on a surface made tacky by three hours of sweating under the tarpaulins, the associates struck two early blows inside the three-over powerplay. Buttler was bowled by Ruben Trumpelmann, before David Wiese, their most seasoned pro, outfoxed Phil Salt with a slower ball. At 13 for two from 13 balls, and with the ball doing plenty, England were in a spot of bother.

Enter Jonny Bairstow, who, after Will Jacks was left out for an extra seamer, breathed life into the innings by thrashing 31 in just 18 balls and adding 56 in five overs with Harry Brook. This injection of momentum was not without a sliding doors moment early on, however, spinner Bernard Scholtz finding the edge of Bairstow’s bat on 15 only for Zane Green to grass the chance. Had it stuck in the wicketkeeper’s gloves, England would have been 29 for three from four overs.

Instead, even with Bairstow eventually holing out, and a mercifully short shower cutting the intended 11-over match down to 10 per side, England managed to muscle their way to 122 for five.

Brook played arguably his most vital white-ball innings to date, walking off unbeaten on 47 from 20 after drilling four fours and two sixes. Moeen Ali and Liam Livingstone added some fairy dust at the end, the two all-rounders delivering selfless cameos that saw both clear the rope twice.

Thereafter, as the clouds made way for some warm late afternoon sunshine, the tension began to ease for England. Buttler and the head coach, Matthew Mott, had opted to bolster their attack by drafting in Sam Curran for Jacks and Chris Jordan for Mark Wood. And though the wickets did not tumble, the ploy worked, with Namibia sufficiently squeezed on a tricky pitch. So much so, in fact, that the first player to depart was in fact retired out by his captain, opener Nikolaas Davin swapped out for the big-hitting Wiese after battling to 18 from 16 balls.

Striding out with 82 runs required from the final 24 balls, Wiese did manage to inflict some late damage, crashing 27 from 12 balls before holing out during the last over from Jofra Archer, an over after opener Michael van Lingen had done the same to Chris Jordan on 33. As Wiese walked off raising his helmet to the dugout, it was clear this would be his final match for Namibia. Whether England had played their last match in this T20 World Cup still hinged on events in St Lucia that night.