Gareth Southgate's tactical tweaks were vindicated by England's triumph over Germany on Tuesday, but the manager admitted he knows he would have been "dead" if he had got it wrong.
England took down Germany 2-0 on Tuesday with Raheem Sterling and Harry Kane each scoring in the second half to seal a spot in the quarter-finals.
Before kickoff and throughout a tense first-half, Southgate came under fire for opting to use a 3-4-3 system, one which did eventually lead England to victory over their rivals.
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What was said?
“You know you change the shape, you pick certain personnel in place of others and if it goes wrong you’re dead," Southgate told BBC One. "We had to go about it in the way we believed. We wanted aggressive pressure all over the field and we felt that to match them up was the right way of doing that.
"We felt that speed in behind Harry would cause them problems. I thought that Bukayo [Saka] and Raheem really created that jepoardy in behind their backline right from the start. We also defended brilliantly and our goalkeeper was immense. It was a tremendous performance.”
What did Southgate change?
Southgate had previously stuck with a four-at-the-back system to guide England through their three group stage games.
He set up the Three Lions in a 4-3-3 in each of their first two matches, a win over Croatia and a draw with Scotland, before inserting Jack Grealish into a 4-2-3-1 for the third game against the Czech Republic.
'A brilliant afternoon'
Southgate went on to hail his team for making the country proud, moving past the demons that Germany had created throughout the two teams' history, but he says wins like Tuesday's won't matter if England slip up down the line as he called for his team to build on this momentum going forward.
“I just thought it was a brilliant afternoon,” Southgate said. “We talked about bringing enjoyment to the nation and afternoon’s like that are what it’s all about.
"The players were absolutely immense right through the team. The fans were as well - only 40,000 but it was as good an atmosphere as I can remember in Wembley.
"We played extremely well, I think we deserved the win but I’ve had to say to them straight away, 'Look, I’m the party pooper, because if we don’t capitalise on Saturday now then it doesn’t count for anything'."
He added: "When I got in the dressing room, they were talking about Saturday already. It has been an immense performance but at a cost emotionally and physically. We need to make sure we recover well. It is a dangerous moment for us.
"We will have that warmth of the feeling around the country that we will only have to turn up to win it but it will be an immense challenge. I think the players know that. They have been to the latter stages before and know how difficult that has been. Their feet are on the ground but they should feel confident from the way they played and manner of the performance.
"We came here with an intention and we have not achieved that yet. We haven't put together a semi-final win after a quarter-final win since 1966. These boys keep writing history and I think we have a chance again. We have only been to one European Championship semi-final and we have a chance to do something special."