Germany could face a humiliating first-round exit from the World Cup in Russia unless they rediscover the form that propelled them to glory in Brazil in 2014 in a crunch match against Sweden on Saturday.
Joachim Loew's defending champions slumped to a 1-0 defeat against Mexico in their opening match, paying the price for a calamitous first half in a performance that drew stinging criticism.
Lothar Matthaeus, the 1990 World Cup-winning captain, said he had not seen a Germany team "so weak at a big tournament for a long time" following the loss in Moscow.
The holders will likely be without defensive pillar Mats Hummels due to a neck injury, while striker Marco Reus could be handed a start after a bright 30-minute cameo off the bench against Mexico.
"Everyone is ready to fight for their lives," said forward Timo Werner, who is again set to lead the Germany attack.
With 10 World Cup goals to his name, Germany will also expect more from Thomas Mueller at his third World Cup.
"The pressure is terrifically high, but we won't win both games if we beat ourselves up internally and look for the mistakes in each other," said Mueller, with Germany set to meet South Korea in their final match.
"Our day of destiny" was the headline in Germany's top-selling Bild newspaper.
Sweden beat the Koreans 1-0 in their Group F opener.
"This is really what you spend your whole career and life working towards. It is an extraordinary opportunity to be involved in a World Cup match like this," said Sweden boss Janne Andersson.
"Whether we knock out Germany is one thing, but we have a chance to qualify and that is extraordinary."
- Lukaku on Ronaldo's heels -
Belgium moved to the brink of the last 16 after crushing Tunisia 5-2 as Romelu Lukaku scored twice to join Cristiano Ronaldo on four goals for the tournament.
Lukaku's double was the first time that a player has scored two or more goals in consecutive World Cup games since Argentine great Diego Maradona achieved the feat in 1986.
Eden Hazard also netted twice and Michy Batshuayi put the cherry on the cake at the Spartak Stadium in Moscow with the fifth as a team rated as dark horses for the title showed their pedigree. Dylan Bronn and Wahbi Khazri scored the goals for Tunisia, who look doomed.
Next up for the Belgians is a blockbuster clash with England on Thursday that is likely to decide who finishes top of Group G, providing England beat Panama on Sunday.
The England camp has been embroiled in a row with journalists covering the team after photographers snapped pictures of the expected lineup for the Panama game that assistant coach Steve Holland was holding.
Panama coach Hernan Gomez said he had no hesitation in announcing his own lineup 24 hours before the match and said knowing that England were set to draft in Marcus Rashford and Ruben Loftus-Cheek made no difference to his plans, nor "gives me any advantage".
In the day's second game, Mexico head into their showdown with South Korea after a memorable win over Germany, but a misstep in Rostov-on-Don would undo all that good work.
The Mexicans will be looking for more goals from explosive 22-year-old Hirving Lozano, who showed in scoring against Germany that he could be one of the stars of this World Cup.
South Korea, and Asia's best player Son Heung-min, will hope to draw inspiration from Asian rivals Japan as they bid to avoid a premature end to their Russian adventure.
Germany coach Joachim Loew faces a crunch match against Sweden
Germany will be looking to Thomas Mueller for goals against Sweden
Romelu Lukaku and Cristiano Ronaldo both have four goals