A roar of frustration from the home fans, they think Ruben Dias has brought down Roland Sallai. The referee keeps his nerve and waves play on.

Full-blooded challenges from both sides in these early stages. All 22 players are putting their all into it, no doubt feeding off the energy from the crowd.

Cracking start to the game.

Oof! A stinger as Diogo Jota runs onto a through ball and thumps a powerful effort at goal but it is straight at the goalkeeper.

Cristiano Ronaldo won't be happy, he was in loads of space to Jota's left. The pass was definitely the better option.

Image source, Getty Images

John Bennett
BBC World Service Sport at the Puskas Arena

Unbelievable being in a full stadium again here in Budapest. A real attack on the senses. The noise in the ground in deafening when the fans whistle. Amazing atmosphere. Pretty surreal to look at all the red shirts in the seats after the last 16 months we’ve had.

Plenty of possession from Portugal in these early stages. Cristiano Ronaldo's first touch sees him win a throw and that prompts a roar from the supporters in the stands.

Ronaldo has a wry smile on his face. He'll be loving playing in front of a huge crowd again, even if they are not all cheering for him.

Chris Sutton
Former Premier League striker on BBC Radio 5 Live

What an atmosphere.

If you can't be inspired by this, you won't be inspired by anything. What an opportunity for the Hungarian players.

Mark Willis: How is Pepe still playing at 38?! Still with his red card record, he's not likely to be on for the full 90 minutes!

Chris Sutton
Former Premier League striker on BBC Radio 5 Live

Hungary you have to think that they have to sit in, have to be difficult to beat and have to play on the counter attack.

Set pieces are going to be absolutely key. From Portugal's point of view, with this group there is a risk if they're not at it today.

But you look at their team and they have strength and depth right through it and they have Ronaldo of course. He's the player that will lift the Portuguese team.

The Hungary fans do their version of the Icelandic thunderclap that we heard at Euro 2016 before the hosts get this Group F opener under way!

Wow!

As the Hungary national anthem concludes the Puskas Arena turns into a cauldron of noise like we haven't heard for well over a year.

Superb.

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Spinetingling!

A huge roar from the 60,000 strong crowd as Hungary head out onto the pitch, before Cristiano Ronaldo leads out the Portuguese team.

Now time for the national anthems.

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BBC Sport looks at Cristiano Ronaldo's journey at the European Championship, from teenage tears in 2004 against Greece, all the way through to winning the tournament as Portugal's captain at Euro 2016.

Watch Cristiano Ronaldo: Impossible to Ignore here on BBC iPlayer.

And read Emlyn Begley's stats-laden piece on Ronaldo here.

Portugal are the team to follow for those of us who are of an age when we think our own football career is over.

Wayne Ellis: Expecting goals, goals and more goals here, although not quite as many as their game in Euro ‘16. 3-1 Portugal

Alex Bysouth
BBC Sport

Image source, Getty Images

The city helped produce one of the most talented generations the world has witnessed. It had a hand in the formation of the European Cup. Its coffee houses played host to the game's early deep-thinking tacticians.

Budapest may not be the hotbed for budding footballers and coaches it once was, but the Hungarian capital is set to be showcased on the international stage once more as it hosts four games at the European Championship.

Under Italian coach Marco Rossi, the former Brescia and Sampdoria defender, the Magyars are experiencing a revival - though progress will be tough, given they have been drawn in a daunting group that also includes Germany.

But no matter whether Hungary make it into the knockout stages, this homecoming offers fans in Budapest a chance to enjoy a footballing renaissance.

Read more and the city and the team here

Mark Lawrenson
BBC football expert

Hungary were in the same group as Portugal at Euro 2016 and ended up topping it after a thrilling 3-3 draw with the eventual tournament winners.

There is no chance Hungary will finish top of Group F and, on paper, this talented Portugal side should have too much for them - but the game is being played in Budapest, so I am going to go with a draw.

Lawro's prediction: 1-1

Those seats are filling up as kick off approaches. Feels so strange to see a stadium so full!

Image source, Getty Images

Despite the 60,000 strong crowd, this chap will definitely still stand out.

Image source, Getty Images

Build up to the first game of the day is on BBC Radio 5 live and BBC Sounds now.

Image source, Getty Images

Christian Eriksen is in the thoughts of fans everywhere as the Denmark star, thankfully, looks to be recovering well.