Marseille - Anything less than a win over Russia on Saturday could scupper England's Euro 2016 hopes, goalkeeper Joe Hart has warned as Roy Hodgson's new-look Three Lions bid to end 50 years of heartache.
England take on an injury-depleted Russia at Marseille's Stade Velodrome desperate to avoid a repeat of the 2014 World Cup when an opening defeat to Italy was followed by another, 2-1 reverse to Uruguay.
Russia are also anxious to put a miserable World Cup behind them.
In the year of the 50th anniversary of England's 1966 World Cup triumph, their sole victory at a major finals, belief is growing that Hodgson's young side can shock bigger favourites like Germany and Spain.
But Hart, one of the England campaigners stunned by the early return from Brazil, said winning their "most important game" will be key if they are to face Group B rivals Slovakia and Wales with confidence.
"Saturday is our most important game and then we're going to look to set the group up," Hart said at England's base in Chantilly near Paris.
"And then we're going to look to win every game that comes next and see where that takes us."
WORLD CUP HEARTACHE
For the Manchester City 'keeper, being "ruthless at both ends of the pitch" will go a long way to making sure they do not return home earlier than anticipated.
"It probably stood out the most in the two games that we lost in the World Cup. We could have walked off easily with two victories, but we didn't," he added.
On paper, England start as favourites to make a winning start to the campaign.
Hodgson has assembled the youngest England squad at a major tournament since the 1958 World Cup, putting faith in youngsters such as striker Marcus Rashford, 18, centre-back Chris Smalling, 25, and 26-year-old right-back Kyle Walker.
Rashford, still stunned at his recent call-up, scored only three minutes into his England debut in a 2-1 win over Australia, while Smalling has been a rock at the back for Manchester United.
After a Premier League season dominated by champions Leicester City and title rivals Tottenham, Jamie Vardy and Harry Kane are set to shoulder England's goals quest in a likely three-man attack alongside veteran Wayne Rooney.
Tottenham striker Kane said he hopes to remedy the perennial problem of the players failing to replicate their club form on the international stage.
"Of course it is always difficult when you come away with England," Kane said after a 1-0 friendly win over Portugal last week.
"You haven't got a lot of time to prepare like you do for your clubs. But we are England internationals. You have to be able to cope with that."
Russia coach Leonid Slutsky, meanwhile, will have to do without injured central midfield pair Alan Dzagoev and Igor Denisov as they look to make amends for their own early departure from Brazil.
Smalling said Artem Dzyuba, the 1.96 metre (6ft 5in) tall Zenit St Petersburg striker who has scored nine goals in 18 international appearances, could be the biggest threat.
"Our two central defenders will have to be very physical and aggressive against him. As defenders in the Premier League we are used to big guys and those challenges, and it's something we enjoy as centre-backs," he said.
After a flawless Euro 2016 qualifying campaign, Hodgson and England are now hoping the Three Lions live up to expectations.
But speaking after a stirring 3-2 victory over world champions Germany in March, the 68-year-old was characteristically cautious when asked if his side could win the tournament.
"We still don't really know how this young group would perform in tournament conditions against much more experienced teams like Germany, who are used to reaching finals, and France as the home nation.
"But I believe in the team. Absolutely."