Al Jazeera picks out the four key matches in this round:

⚽ Germany vs Denmark

When: June 29, 9pm local time (19:00 GMT)

Where: BVB Stadion in Dortmund

Germany and Denmark will meet in a rematch of the 1992 Euro final when they face off in Saturday’s match in Dortmund. While hosts Germany have been unbeaten in the tournament with two wins and a draw, Denmark is yet to celebrate a win, drawing all their group games while scoring only twice.

Heading into the match as underdogs, Denmark will seek historic inspiration from their miraculous Euro 1992 finals performance in Gothenburg. In that match, they pulled off one of the biggest final upsets ever, beating then-world champions Germany 2-0 to win their first and only major football title.

“It’s a strong team we’re going to face and a little bit like the big country against the little country,” Denmark’s assistant coach Christian Poulsen told reporters ahead of Saturday’s round of 16 clash. “But we’re going to go into the battle and hope we can do the same as we did in ’92.”

The Danes will rely on veteran midfielder Christian Eriksen and forwards Rasmus Hojlund and Jonas Wind to challenge Germany, who have a star-studded squad featuring Euro 2024’s joint-second top scorers Jamal Musiala and Niclas Fullkrug, as well as breakout star Florian Wirtz.

Before the knockout match, Germany coach Julian Nagelsmann will face a tough decision: Retain his faith in the under-performing Kai Havertz in the starting lineup or start Fullkrug after his stoppage-time equaliser off the bench in the last game against Switzerland.

Historically, Germany is close to unbeatable once they reach the knockout stage at the Euros. Of the 10 times Germany has made it through, they have gone on to reach the semifinals on nine occasions and the final six.

The Germans are level with Spain with three European Football Championship titles. Beating Denmark on Saturday moves them one step closer to a record fourth title – and with the added motivation of doing so as the Euro 2024 host nation, as well as being the perfect send off for German superstar Toni Kroos, who will retire from football after the tournament.

But Denmark, who reached the semifinals at the last edition of Euro 2020, will be no easy pushover for the Germans.

⚽ France vs Belgium

When: July 1, 6pm local time (16:00 GMT)

Where: Dusseldorf Arena in Dusseldorf

France and Belgium have one thing in common: Both teams have struggled in attack at this tournament.

While two-time world champions France have not scored from open play so far, Belgium have scored only twice in three matches.

Those stats sound bizarre given the attacking talent in both these star-studded teams – the French boast the likes of superstar Kylian Mbappe and experienced forward Antoine Griezmann, while Belgium are blessed with one of the best playmakers in the world, Kevin De Bruyne, and towering striker Romelu Lukaku.

Despite bagging only two goals in the group stage – an own goal against Austria and a penalty scored by Mbappe – France defender Saliba is confident his teammates will step up in the knockout against Belgium.

“It’s clear that we have to be more dangerous with our set pieces, especially me. I think I haven’t even touched one, so we can do better,” Saliba said.

Attacking issues are not the only problem Belgium are dealing with. Fans booed and whistled the team after their goalless group match draw with Ukraine in Stuttgart and captain De Bruyne told his players to leave the field without thanking the supporters.

Defender Thomas Meunier said the fan reaction was “out of proportion”, adding that the team “always plays to win”.

Belgium, who are still searching for their first major football title, have shown very little intent at the tournament for fans to believe they can outclass France, who have won the Euros twice and are considered by many pundits to be the tournament favourites.

Monday’s contest will be the 76th meeting between the two sides, although their first in the Euros since 1984.

⚽ Austria vs Turkey

When: July 2, 9pm local time (19:00 GMT)

Where: Leipzig Stadium in Leipzig

Playing rapid and entertaining football, Austria and Turkey were two of the most exciting teams in the Euro 2024 group stage.

Not many expected Austria to win a group which included tournament heavyweights France and the Netherlands, but Ralf Rangnick’s young side pulled off the unthinkable with their excellent attacking display.

No longer playing with a defensive mindset, Austria scored six goals in the three group matches with six different players registering a score, suggesting the team is well-balanced and unselfish in attack.

“It’s incredible to finish top of the group that was the hardest possible based on UEFA coefficients,” Rangnick said. “We started with an unlucky own goal against France, dealt with all the pressure put on us to win against Poland, and then to end as group winners is something very special,” added the ex-Manchester United interim manager, who is known for his counter-pressing tactics.

The Austrians, who have little star power and haven’t gone beyond the last 16, entered the tournament as dark horses but have now elevated their status to title contenders. Standing in Austria’s way at the first hurdle will be familiar foes Turkey, whose campaign has been nothing short of dramatic.

Arda Guler and Hakan Calhanoglu were among the goalscorers as Turkey netted an impressive five times in the group stage. But they also leaked an equal number of goals, revealing the lack of solidity in defence.

Austria won 6-1 when these teams last met in a friendly in March but Turkey, the 2008 Euro semifinalists, are high on confidence this time and will likely pose a better challenge.

However, the Turks will play the round of 16 match without their inspirational captain Calhanoglu, who is suspended after picking up two yellow cards. His huge absence may be all the motivation the Austrians need as they attempt to reach the quarterfinals of the Euros for the first time.

⚽ Portugal vs Slovenia

When: July 1, 9pm local time (19:00 GMT)

Where: Frankfurt Arena in Frankfurt

Pressure will be on Portugal to regroup quickly after their second-string side suffered a shock 2-0 defeat to tournament debutants Georgia in the final Euro 2024 group game on June 26.

As they gear up to face Slovenia in the last 16, most fans would pick Portugal as the clear favourites, but a quick look at history and the form guide might suggest otherwise.

Portugal have faced Slovenia only once – losing 2-0 to them in a friendly in March 2024. Cristiano Ronaldo was part of the team that started in that game, though Portugal were missing their key duo of Bernardo Silva and Bruno Fernandes in the midfield.

Both Silva and Fernandes have found the net at Euro 2024, but Portugal’s ageing superstar forward and captain Ronaldo has yet to get on the scoresheet, despite having the most attempts on goal.

In what must be a worrying development for Portugal, for the first time in his career, the 39-year-old Ronaldo has not scored in the group stage of a major international tournament.

A Portugal side that has not hit top gear will likely face problems against Slovenia, who prefer sitting deep and frustrating their opponents, as they demonstrated against England in a 0-0 draw in their final group stage match in Cologne.

“Slovenia are a team that plays like a club, with brutal defensive synchronization and two influential strikers. We need to prepare well for the game, but this is not a friendly,” Portugal’s coach Roberto Martinez said, referring to his side’s loss to Slovenia back in March.

The Slovenians, playing in the Euros knockouts for the first time after grabbing three draws, are also dangerous on counterattack.

Key striker Benjamin Sesko, standing a towering 1.95 metres (6.5 feet) and blessed with outstanding athleticism for a player his size, is one of Europe’s most exciting young forwards and is considered Slovenia’s big matchup threat up front versus Portugal.