World Cup heavyweights Spain and Portugal can lock down spots in the last 16 on Monday, as hosts Russia ride a wave of national euphoria into their clash with Uruguay.
Spain crashed out in spectacular fashion in the group stage four years ago in Brazil, but the 2010 champions are on course to reach the knockout phase in Russia despite sacking their coach on the eve of the tournament.
They require a point against Morocco in Kaliningrad to secure qualification, and new coach Fernando Hierro promised they would not underestimate a North African side playing for pride.
"We can't afford to relax... We need to be awake with our eyes open and be aware that Morocco aren't going to give anything away," warned Hierro, who replaced Julen Lopetegui a day before the tournament started.
Portugal meet former coach Carlos Queiroz and Iran in their final Group B game in Saransk. Cristiano Ronaldo's side will advance with a draw, but a win for Iran would see the European champions or Spain suffer a shock exit.
"Both teams have something to win and also to lose, neither has more to win than the other," said Portugal boss Fernando Santos.
In Group A, Russia will bid for a third straight win after a stunning start to the tournament for a side initially written off as no-hopers.
Stanislav Cherchesov said he would stick with the same line-up that beat Egypt 3-1 as Russia lock horns with Uruguay in Samara, with first place on the line.
"We don't choose our opponent in the last 16. We're not doing the calculations, we've never done them," said Cherchesov.
"And in any case we don't have the choice, they play after us. We know both teams, the football gods will decide."
Colombia coach Jose Pekerman dedicated his side's crucial 3-0 win over Poland on Sunday to midfielder Carlos Sanchez after reports the midfielder received death threats for his red card against Japan.
Sanchez has had "a very hard time" dealing with the fallout from his third-minute sending-off in the 2-1 defeat to Japan in Colombia's opening game, Pekerman said.
He said he spoke for the whole squad when he dedicated Colombia's win over Poland to the 32-year-old player.
"This victory is dedicated to Carlos Sanchez, because he's had a very hard time in the past days. I want, and we want, to share it with him," he said.
Pekerman added: "We received certain information, but I can't confirm anything. The player was deeply affected by this matter.
"It went beyond football. It's a game that we play with a lot of hard work and dedication, but these things should not be taken lightly.
"Whether it's confirmed or not... this is extremely painful."
It evoked memories of the chilling murder of Colombia player Andres Escobar, who was killed after his own goal led to defeat to the United States in the 1994 World Cup and Colombia's elimination from the tournament.
Robert Lewandowski's Poland were unceremoniously dumped out following the loss to Colombia, who can guarantee a place in the last 16 by beating Senegal in their concluding game in Group H.
The west Africans and Japan are both in control of their destiny following a 2-2 draw in Yekaterinburg that left both nations on four points.
Kane streaks ahead
England striker Harry Kane surged ahead of Ronaldo and Romelu Lukaku in the race for the World Cup golden boot after hitting a hat-trick in a 6-1 demolition of Panama on Sunday.
The Tottenham star scored twice from the penalty spot before deflecting in a Ruben Loftus-Cheek drive with his heel to make it five goals from two games as England sealed safe passage to the last 16.
"I'm very proud. Not many players get to score a hat-trick in the World Cup," Kane said.
Gareth Southgate's side lead Belgium at the top of Group G by virtue of having received one less yellow card going into their showdown in Kaliningrad on June 28.
Mohamed Salah is likely to start Egypt's final match against Saudi Arabia on Monday in a fixture between two eliminated sides in Volgograd.
But Egypt's 45-year-old goalkeeper Essam El Hadary may have to wait to come off the bench to set a record as the oldest player ever to appear at a World Cup.
He would smash the age record set by Faryd Mondragon in Brazil four years ago.
The Colombia goalkeeper was 43 years and three days old when he played against Japan in a 4-1 group stage victory.