Jonty Colman
BBC Sport Journalist

Image source, BBC Sport

Waveform technology that mirrors cricket's Snickometer (more commonly known as Snicko) judged that after the free-kick was taken, Sweden and Liverpool striker Alexander Isak got the faintest of touches on the ball - and when he did, Svanberg had moved back into an onside position, meaning the goal was allowed.

The Trionda match ball, made by Adidas for this year's World Cup, has a microchip in it that can detect when the ball has been touched.

It is part of Adidas' Connected Ball Technology, allowing precise data such as every individual touch of the ball with a boot or hand to be immediately sent to the Video Assistant Referee in real time.

Adidas say the technology "enables faster in-game officiating decisions and more insight into gameplay than ever before."

When Svanberg's goal was awarded, replays showed a flat line sensor on the screen that had a spike as the ball passed Isak's outstretched foot, confirming that he got a touch on the ball that was not necessarily obvious to the naked eye.

Image source, Getty Images

Sweden's fourth goal in their 5-1 win against Tunisia also provided a talking point, as it was controversially awarded following the use of Snickometer technology.

Mattias Svanberg scored just 18 seconds after coming on as a substitute in the second half by converting a Yasin Ayari free-kick during Graham Potter's side's 5-1 win.

Initially, Svanberg had been declared offside at the time the free-kick was delivered.

Following protests from Sweden's coaching staff and players and after a check by the Video Assistant Referee (VAR) team, the goal was later given.

And after just 18 seconds, Svanberg has recorded the fastest goal by a substitute in World Cup history.

Before we move on, let's have a look at some of the other talking points from day four's World Cup action, starting with the colour brought by the Netherlands and Japan supporters in Arlington...

Simon Stone
BBC Sport Manchester United reporter

Manchester United fans will be delighted at Amad Diallo's last-minute winner for Ivory Coast.

Amad is a crowd favourite at Old Trafford but disappointed this season.

He managed just two goals and four assists in 33 games and United head coach Michael Carrick repeatedly had to come out and defend the 23-year-old at the end of the season, when Amad was linked with a return to Sunderland, where he previously had a successful loan spell.

Amad was one of the players who benefited from previous manager Ruben Amorim's change of system and scrapping the wing-back positions has not quite worked out for him as yet.

I never got the impression United were looking at letting Amad go, but they do need him to get better. His stunning late effort last night will fuel confidence it will happen.

There have been 22 editions of the World Cup since 1930, but no African team has ever won the global showpiece.

In that time 49 sides have represented the continent, taken from 13 countries, yet Africa has produced just one semi-finalist.

That historic landmark came four years ago at Qatar 2022, when Morocco broke new ground for the world's second-largest and second most populous continent.

Africa had three quarter-finalists - Cameroon in 1990, Senegal in 2002 and Ghana in 2010 - before Morocco upset Belgium, Spain and Portugal on their way to the last four in Qatar.

Image source, Getty Images

Image source, Getty Images

Manchester United winger Amad Diallo says Ivory Coast have come to the World Cup "to make history" by making it out of the group stage for the first time.

The 23-year-old was speaking after firing in a late goal to seal a 1-0 win against Ecuador in their opening game of Group E in Philadelphia.

“We had to stay focused," said Amad, after helping Ivory Coast edge a tight encounter.

"We knew it was going to be a difficult match because we know the Ecuadorian players – they’re physically very strong.

“We came here to make history. We still have two more matches ahead of us, and we need to approach them with the same mentality and try to win them.”

Ivory Coast have played in three World Cups - 2006, 2010 and 2014 - but failed to make it out of the group stage on each occasion.

Curacao move on to Ecuador next, while Germany face Ivory Coast in a battle of Group E's top two.

Ivory Coast match winner Amad Diallo is keen for his side to build on their positive start as the country bids to go further at a World Cup than they have ever done before...

Alex Hoad
BBC Sport journalist

Image source, Getty Images

It was fun for a while as Curacao showed great spirit and had Germany concerned when they levelled.

There may be lingering headaches too, especially for their supporters, following their debut on football's biggest stage - perhaps fitting for a nation most famous for its alcoholic drink of the same name.

But the emotions will be bitter-sweet, which also seems apt, after their dream start was ruined by a ruthless Germany.

History was made as the Blue Wave were introduced to the world and Livano Comenencia struck a memorable first goal, while boss Dick Advocaat, once of Sunderland and Rangers and a three-time Netherlands boss, became the oldest coach in World Cup history at 78 years and 260 days old.

Curacao were, however, the first debutants in 72 years to lose by six goals in their first match, following South Korea's 9-0 defeat by Hungary.

Labelled the biggest mismatch at the tournament according to the bookmakers, it was always going to be a tough test against a side as experienced as Germany.

They showed enterprise in attack, but were too open at the back, and their best hopes of making an impact at the tournament were always going to be in the remaining group games against the Ivory Coast and Ecuador.

Advocaat admitted: "We expected to do more, but they were too strong. We conceded three easy goals and 4-1 would have been a better score.

"Despite this 7-1 outcome, the joy of the fans is fantastic. This is not a disgrace, we can still be proud. We still have two games to go and those could end differently.

"The players will not be downcast, it was still great to play in this game."

Of course, there is an asterisk against the eye-catching performances of Florian Wirtz, Kai Havertz et al for Germany in their World Cup opener as their 7-1 victory was against minnows Curacao.

Tougher tests are sure to follow in Group E against Ivory Coast and Ecuador, but after failing to make it out of their group in the last two World Cups, Germany can now feel confident of progressing to the knockout stages this time around...

Remaining matches:

Saturday 20, June

• Germany v Ivory Coast (21:00 BST)

Sunday, 21 June

• Ecuardor v Curacao (01:00 BST)

Thursday, 25 June

• Curacao v Ivory Coast (21:00 BST)
• Ecuardor v Germany (21:00 BST)

BBC Radio 5 Live

Image source, Getty Images

Former England striker Chris Sutton, in Houston for BBC Radio 5 Live, on Florian Wirtz: "The mitigation must be that this was Curacao, but the Liverpool fans who watched the game, especially in the first half, would be wondering if it was the same Florian Wirtz who played for them last season.

"He looked happy in a German jersey, at ease and playing with freedom."

Sutton added: "He was sharp off the left, drifting inside to play quick, incisive passes. He was creative and cunning. He looked unburdened. He was a real menace with Jamal Musiala."

Phil McNulty
BBC Sport chief football writer at Dallas Stadium

Image source, Getty Images

Florian Wirtz arrived at Liverpool from Bayer Leverkusen last summer amid great fanfare in a then-British record £116m deal - but remained an enigma as he fell far short of expectations.

Liverpool still have huge hopes for a gifted attacking player who has only just turned 23, which means one of Iraola's main tasks is to find a settled position for the German to release the talent he demonstrated before moving to Anfield.

This is why Iraola will have been intrigued by what he saw from Wirtz in Germany's 7-1 win against Curacao in their opening World Cup game.

The context must be that this was against a side ranked 82nd in the world, but in the colours of his country and in favourable conditions, Wirtz showed some golden touches.

In Houston, Wirtz played on the left, perhaps giving Iraola food for thought, especially as Cody Gakpo had a poor season in that position. He created Germany's opening goal for Felix Nmecha with the sort of delicate touch and quick thinking that eluded him for much of last term.

Wirtz had 39 touches in the final third, instrumental as Germany ran riot.

Mario Melchiot
Former Netherlands defender on Football Daily

You always want to start well and that's definitely what the Germans did. They have a lot of talent. When you look at the German side every tournament we go to, we can never say we are not thinking about the Germans. It's impossible.

The way they kicked off, the scoreline 7-1 is a lot. In the system, Germany are great when they keep it compact.

As soon as you stretch the team open and you get them in the pocket, then it becomes a one-v-one and then I don't know if they're going to be tested and that's what I want to see.

Image source, Getty Images

Alex Hoad
BBC Sport journalist

Image source, Getty Images

Four-time winners Germany overcame a brief scare from World Cup debutants Curacao before turning on the style to win their Group E opener in Houston.

Die Mannschaft went ahead in the sixth minute with the tournament's earliest goal so far coming from a delightful curling effort from one-time England youth international Felix Nmecha after a classy Florian Wirtz touch.

But they were stunned by a historic leveller from the smallest nation ever, by size and population, to take part in a World Cup. With around 155,000 inhabitants, the Caribbean island of just 171 square miles is smaller than the Isle of Man with a population the same as Huddersfield.

Zurich midfielder Livano Comenencia wrote his name in folklore on 21 minutes with a left-footed drive from the edge of the box which deflected past Germany keeper Manuel Neuer.

But Germany re-established their lead after the hydration break through Nico Schlotterbeck's flashing header from Nathaniel Brown's corner to the near post.

The pressure intensified and a calm penalty from Kai Havertz in the fifth minute of first-half stoppage-time - following a rash lunge on the impressive Nmecha by Riechedly Bazoer - gave the eight-time finalists breathing space.

Just 69 seconds after the interval Jamal Musiala fired in an angled finish from Joshua Kimmich's neat pass to signal Germany's intent as they took control of the game.

Left-back Brown lashed home a volley after a neat flick from substitute Deniz Undav, who then swept home a sixth from Kimmich's pass.

The former Brighton forward, now at Stuttgart, then set up Havertz for Germany's seventh goal two minutes from time, a lovely dink over Curacao keeper Eloy Room to seal a dominant success.

Chris McKenna
BBC Sport reporter

Manchester United winger Amad Diallo scored a superb 90th-minute winner as Ivory Coast beat Ecuador in Philadelphia.

It was a stunning finish as the substitute opened his left foot to divert the ball into the corner after a powerful run from Wilfried Singo - and it ended a 19-game unbeaten run stretching for almost two years for Ecuador.

Amad was a surprise exclusion from Ivory Coast's starting line-up on their return to the World Cup for the first time in 12 years.

But he made a major impact with the winner which gives them a huge chance to qualify out of Group E - which also includes Germany and Curacao - and reach the knockout stages for the first time in their history.

Premier League players also played a key role in both opening matches in Group E...

Let's have a recap.

Here's a round-up of what we have focused on so far after a day of World Cup action where Premier League stars have taken centre stage:

• Watch highlights from the latest World Cup matches - all the highlights in one place

• The Premier League factor - how players in the English top flight have taken centre stage
• Sweden thrash Tunisia - great start for Graham Potter's men in Group F
• Japan come from behind against Netherlands - resilient Japan fight for important point
• Get Involved - Should Sweden be considered dark horses? - send us your thoughts

Rory Smith
Football Correspondent for The Observer on BBC Radio 5 Live Breakfast

I was impressed with Japan, I thought they were very good [against the Netherlands] and their form is excellent. They also won at Wembley a few months ago.

Image source, Getty Images

What of the other dark horse of Group F?

Japan head coach Hajime Moriyasu said before the tournament started that his side's goal was to win the World Cup.

The country has never been past the last 16 before but Japan beat Germany and Spain in the group stages at Qatar 2022, before losing to Croatia on penalties in the first knockout round.

Since then they have beaten Germany and Brazil in friendlies and warmed up for this tournament with wins away to Scotland and England in March.

After battling to a point against the Netherlands in their opener in Dallas, Moriyasu's side can effectively seal their progress from Group F with a win against Tunisia on 21 June.

They then face early group leaders Sweden in their final game on 26 June. Could that match determine who qualifies as group winners?