Germany face a fight for World Cup survival in the early hours of November 28 (2am Cambodian time) in a must-win clash with Spain as Japan and Belgium look to seal their place in the last 16.
For the second World Cup running, Germany will suffer a humiliating exit in the group phase if they lose their Group E clash with in-form Spain at the Al Bayt Stadium.
The four-time champions were left staring down the barrel of elimination after crashing to a shock 2-1 loss to Japan in their opening fixture on November 23.
The prospect of an early German exit – four years after bowing out at the same stage at the 2018 finals in Russia – was practically unthinkable before the tournament.
German coach Hansi Flick insisted on Saturday his team had the quality to bounce back against a rampant Spain team who obliterated Costa Rica 7-0 in their opening game.
"We have a team that has quality, that can implement the things [we are working on], and we are very positive about it," Flick said.
"We need to arrive with courage and with faith in our quality for this game against Spain."
Spain coach Luis Enrique meanwhile says his team face a "beautiful challenge" as they chase a win that will see them into the last 16.
Luis Enrique cautioned however that Germany's World Cup pedigree – they won their fourth title in 2014 – meant nothing could be taken for granted.
"They are world champions, when you look there are four stars on their shirt," the Spain coach said.
"I have a lot of respect for their players, they are world class, and their history is there to see."
Past their peak
A Spanish victory would mean Japan would also secure their passage to their knockouts if they beat Costa Rica.
On paper, a place in the last 16 is beckoning for the skilful and energetic Blue Samurai against an ageing Costa Rica team that looked to have been reeled in by Father Time during the dissection by Spain.
Japan captain Maya Yoshida warned on November 26, however, that there was no danger his team would take the Costa Ricans for granted.
"They got hammered in their previous game so I think they're really going to go for it," Yoshida said.
"There are no easy teams at the World Cup. They will be fighting for the pride of their country and we have to be mentally prepared to deal with that."
Elsewhere on Sunday, 2018 third place finishers Belgium could advance with a victory over Morocco in Group F.
Belgium captain Eden Hazard admitted on November 26 that the Red Devils' vaunted "Golden Generation" is also past its peak – but insisted they remain World Cup contenders.
"To be fair I think we had a better chance to win four years go," the 31-year-old said.
"The team was better four years ago but still we have the quality to win games and to win the competition. We have a few guys, they are a bit older now but we have experience and the best goalkeeper in the world [Thibaut Courtois]."
Sunday's other Group F game sees 2018 runners up Croatia look to edge towards the last 16 against Canada, playing in their first World Cup since 1986.
On November 26, France became the first team into the second round after two goals from Kylian Mbappe inspired a 2-1 win over Denmark in Group D.
Argentina also resurrected their campaign following a shock opening defeat to Saudi Arabia after goals from Lionel Messi and Enzo Fernandez secured a 2-0 win over Mexico in Group C.
"We knew that we had to win today, that another World Cup was starting for us and we knew how to do it," Messi said.