Mauricio Pochettino had spent the past few days summoning belief in what the USA might achieve in the face of scepticism. Can they win the World Cup, he was repeatedly asked, to which his stock response was: “Why not? We can dream.” After this hugely impressive 4-1 win over Paraguay in Los Angeles, perhaps Pochettino’s task now is to manage inflated expectations, to temper America’s wildest dreams.

The first half in particular was 45 minutes of perfection, broken only by three minutes of needless hydration. One of America’s nagging concerns in recent years has been the lack of a ruthless striker but Monaco forward Folarin Balogun scored three times, one of which was ruled out for offside, and the last of which was a brilliantly composed and precise finish into the top corner of Orlando Gill’s goal.

That strike wrapped a half full of endeavour and spirit, but also technical quality and intelligent movement. Pochettino has spent most of his two-year reign as manager testing and tweaking, trying to find the right balance between attack and defence, between left and right, and here his team worked in seamless sync.

Sergino Dest was a constant threat on the right wing with his direct dribbling, while Paraguay’s right-back Juan Jose Caceres must have contracted the twisties trying to fend off Christian Pulisic on the opposite side. Pulisic offered creative spark and set up Balogun’s first goal before being replaced at half-time.

“I just got a bit of a kick in the first half, so I’m really hoping that it’s nothing,” Pulisic said after the game. “Taking a little bit of precaution today, but I’m hoping I’ll be fine the next few days.”

USA’s reliance on Pulisic has often weighed heavily on this generation’s star player. His face has been all over billboards and on TV adverts here. But the performance of Balogun up front and Juventus midfielder Weston McKennie stitching moves together in the No 10 role suggested that responsibility will be shared around.

“It’s a dream,” Balogun after his World Cup debut. “It’s a dreamy night.”

This World Cup is not just a test of the USA’s place in the game but a test of the game’s place in the USA. It is now the fourth most popular sport in America, with more fans than ever watching Major League Soccer and more children than ever playing the game. With a World Cup on home soil, there will never be a better platform for America to climb closer to the sport’s summit.

To be in LA over the past few days was to meet two different types of America. The majority only vaguely know the World Cup is happening and have no idea the US are playing in their own city or which players are on the team. They assume “Pochettino” is a type of coffee. It can feel like the World Cup has barely registered in a city this vast, like a damselfly landing on a water buffalo’s back.

But there are thousands of football fans if you look in the right places. US shirts, Mexico shirts, Argentina shirts, people passionate about the game and giddy its greatest show has arrived on their doorstep.

“What is success?” Pochettino keeps being asked. Perhaps it is not a specific knockout round but a feeling, a moment, a late winner that grips the entire country, even those oblivious to what is going on right now. USA’s task here is not so much to win the World Cup as to take the country on an unforgettable ride so that in years to come, the words “that summer of 2026” transport them back to a moment in time when they felt something.

The job of this squad, a diverse band of brothers, is to connect with the American public, and this was the perfect start. The evening began with an opening ceremony and organisers provided all the bombast you’d expect, with a series of musical acts headlined by Katy Perry and a parade of national flags reminiscent of an Olympic Games. Iran’s flag was among the 48, although it was somewhat comical that the event’s MC called for “a round of applause for peace” before kick-off.

There appeared to be almost as many Paraguay fans as US supporters inside this extraordinary spaceship of a stadium, almost as many vertical red and white stripes as horizontal ones, like the world’s most devilish game of Where’s Wally. Like several other games so far there were some empty seats which undermined the wisdom of Fifa’s ticketing policy, although several fans entering the stadium told The Independent they had paid around $1,000 for tickets, so Fifa may not miss a few going unsold.

Donald Trump did not attend but Tom Cruise, David Beckham, Brad Pitt, Halle Berry, Hilary Duff and Vince Vaughn were among the famous faces posted on giant screens with their names captioned beneath them, as they do here. What they witnessed was the standout performance of the tournament so far.

Pulisic danced into the box before drawing the mistake from Bobadilla for America’s first goal, and Pulisic was involved again down the left when he raced into space before squaring for Balogun to convert a sharp first-time finish. Balogun’s second goal was even better, shrugging off a defender before pausing just a moment and then spearing a shot into the top corner.

Paraguay pulled a goal back in the second half through substitute Mauricio, but the US showed off their firepower in reserve when Gio Reyna came off the bench to swerve an arcing finish past Gill to seal three points.

“Poch has said many times, why not us?” added Balogun. “We have to believe. You can’t do anything if you don’t believe in yourself.” By the full-time whistle, there were no more disbelievers.