The blast of the final whistle had barely subsided when a lone voice, down on the touchline, punctured the silence with a scream of 'Yes!'

Aidy Boothroyd had just seen England's ambitions at Euro 2017 take flight following a thrilling second half fight-back, with goals from Alfie Mawson and Nathan Redmond putting England on top of Group A and the head coach's glee was understandable.

His choice of word to celebrate was appropriate, too, as for the opening 45 minutes of this helter-skelter evening, the only one that looked set to be appropriate was 'no'. England could not have come any closer to being eliminated from this tournament but now they can dare to dream. 

Trailing to a header from Martin Chrien, England were dreadful in the first half but thanks to a tactical change at the break, which saw the introduction of Jacob Murphy, England can attack Thursday's decider with Poland riding high.

Having been disappointed with the way England had used the ball in the sterile opening draw with Sweden, Boothroyd decided to switch to a midfield diamond with Jon Swift, the Reading midfielder, taking the place of Norwich winger Murphy.

It was meant to elicit a slick, adventurous performance but the reality was horribly different. The first 45 minutes had to be regarded as the worst offering from an England Under 21 team in four years, on par with the shambles that was produced during the final days of Stuart Pearce's reign.

When they were supposed to be dynamic, England dithered. When composure was needed, they became flustered and even the simple things became too difficult to do properly; they looked frozen, terrified almost. They were passive on the pitch and, alarmingly, the coach was passive too.

A huge number of Slovakians had travelled to make this feel like a home game and, with their players bursting with feistiness, it was clear that England were vulnerable; so it proved in the 23rd minute when the plunged themselves into a crisis.

The goal to which they fell behind typified the way they were playing. It was a simple corner, tossed in from the left by Albert Rusnak, but Everton defender Mason Holgate allowed Chrien to run off him and the midfielder's header looped over Jordan Pickford.

Here was a moment that left them on the brink of submerging. To give you an idea of how fragile England were, the ball was moved around at the back aimlessly. Nobody wanted responsibility; these players wilting like flowers in the sun.

Slovakia's aggression had unsettled them and, for some reason, Boothroyd decided to bicker with the fourth official when half-time had been called rather than head straight down the tunnel to confront the crisis. It was difficult, at this juncture, to see a way back.

But then things changed. Murphy was introduced at the expense of Holgate, who needed rescuing. It appeared madness asking a winger to play in defence but Murphy's ability on the ball would suddenly become a potent weapon.

Within four minutes, England had hauled themselves off the floor. After Swift had won a corner, the ball ended up drifting to the far side of the area and was rescued by Redmond, who in turn picked out Murphy. His delivery was inch-perfect and, at the second attempt, Mawson bundled home.

From nowhere, the Young Lions had the scent of blood. Slovakia began deflating like a punctured balloon and, on the hour, the game had been turned upside down after England launched a classic, lethal counterattack.

James Ward-Prowse had spoken of his desire to inspire like Steven Gerrard and the captain produced a pass of which his idol would have been proud, a 40-yard defence-splitter that allowed Redmond to gallop away. Without breaking stride, he fizzed a right-footed drive into the top corner.

The celebrations, quite rightly, were exuberant, the relief was tangible. From then on, it became a question of whether England could withstand the fightback and it was heartening to see them dig deep. The digging, however, needs to continue if they are to reach the last four.