Jürgen Klinsmann has been here before. The titans of the German football establishment – Franz Beckenbauer, Uli Hoeness, Felix Magath – greeted Klinsmann’s appointment as manager of Die Mannschaft in 2004 with condescending bemusement. They did little to hide their disdain for the California resident in the years that followed, deriding his attachment to America – caffeinated, silly America – as an insult to German football’s stolid, collegiate traditionalism. By the time Germany’s home World Cup rolled around in 2006, that low hum of tutting disapproval had turned into a roar. Beckenbauer famously criticized Klinsmann in public for not turning up to a coaches’ workshop three months before the tournament, and there was much fretting over the team’s sluggish, stop-start progress on the field. But then the World Cup started, and Germany was transformed – from a team of directionless plodders to a tantalizingly mobile outfit committed to attack at all costs.

German football has not been the same since. Sure, a lot of the renaissance in Die Mannschaft’s fortunes over the last decade is down to Joachim Löw, not to mention the youth and development structures that allowed a new generation of talent to flourish – but it all began in 2006. It all began with Jürgen at the World Cup, arms pumping furiously on the sideline, eyes bulging, clapping like a lunatic. Klinsmann’s sheer exuberance provided German football’s resurgence with its originating jolt; Michael Ballack, the captain in 2006, later said he had never met someone “with such a gift for making people so enthusiastic about something”.

Is history repeating itself with the US national team at this Copa América? Klinsmann has calmed down a bit since 2006 – the clapping is more controlled, and you no longer get the impression from his goal celebrations that he would really prefer to be playing on the pitch – but the signs suggest it may be. In their opening night loss to Colombia, the US were clueless, anonymous and overwhelmed. Klinsmann argued after the match that his team had actually played well – the kind of deadpan denial of the obvious that Donald “I am the least racist person there is” Trump might have been proud of.

But Klinsmann kept faith with his starting XI, and has been richly rewarded for that show of loyalty in the two matches since. On Tuesday, against Costa Rica, Klinsmann’s men were thrilling going forward, scoring four goals in a liberating display that made all the labors of the previous month seem like a trick of the mind. On Saturday night, against Paraguay, they took the lead, went down to 10 men, then defended with the discipline, intensity and brutal concentration of a YouTube user counting down the final three seconds before they can skip the ad. The 1-0 win put them through as group winners. Klinsmann’s 2016 US men’s national team is pulling a Germany 2006 on us, and it is wonderful to watch.

It’s hard to shake the sense that Klinsmann remains a tactically naive manager, but momentum often matters more than tactics in tournament football, and there’s little doubt the US now have momentum on their side. Besides, the German got his tactics right last night: he made Bobby Wood the fulcrum of the attack – a logical formation change in light of the Hamburg-bound striker’s demonstration against Costa Rica of how lethal he can be when playing centrally – and tucked Clint Dempsey in behind, with Gyasi Zardes and Alejandro Bedoya encouraged to get wide and run fast.

Paraguay, needing a win to survive in the tournament, had promised to attack and take chances in the first half, and attack they did. But this was a plan that played directly into the home team’s hands, because it allowed the US to settle into the rapid, counter-attacking pattern that fits them best. Dempsey’s goal – created by lightning work down the left flank by Zardes – exemplified the merits of this approach going forward, but it wouldn’t have worked without a solid defensive shield.

And Saturday night, if anything, was about the defense. The pivotal moment of the contest was not Zardes’s assist, neat as it was, but John Brooks’s block on Miguel Almiron after the Paraguayans, in the 10th minute, broke with three men against two. Brooks celebrated the block like a goalkeeper celebrating a penalty save, and with good reason: it set the tempo for the match, a minor classic of the defensive genre whose defining feature was not what got created in the final third, but what got snuffed out. Too often football observers, in their rush to be wowed by the artistry of players further up the pitch, overlook the talents of defenders. Let not these arch-miserabilists, these professional rejecters whose contributions are measured in the negative (shots blocked, passes intercepted, chances killed), be overlooked. Last night the US’s were magnificent.

Protecting a slim lead, the US needed discipline in the second half. Instead, they got a man sent off. In a sense this made life simpler for the home team, because it allowed them to jettison whatever ambition they might have had to extend their lead and focus, instead, on pure, bloody defense. Paraguay’s Derlis Gonzalez is a jewel of a player, a pacy trickster with extravagant close control and the full range of hug-the-sideline party tricks. He seems slightly out of place in this otherwise workmanlike Paraguayan ensemble – an emerald slumming it among the zirconia knockoffs. But working together, Gonzalez and his team-mates threw everything at the US defense. The US defense threw everything back.

Paraguay were Alexi Lalas and the US were Fernando Fiore: the stodgy versus the impenetrable. No matter how hard Los Guaraníes tried to find a way through the home defense, they couldn’t: like a Fiore monologue, the US proved utterly resistant to being broken down. (This isn’t a knock on Fiore, whose zany uncle persona has provided welcome, if at times unhinged, relief from the white guy, stuffed-shirt groupthink that usually prevails on TV coverage of football in this country; it’s more a statement about the persistent, middle America befuddlement of Lalas before the antics of his studio neighbor:“These crazy Latin Americans!”)

Time and time again, Brooks was there to repel the Paraguayans’ thrusts into the area. His anticipation was superb, and he was equally comfortable with his head as with his feet. For those who keep track of his progress in the Bundesliga, this felt like no surprise – last season, in helping Hertha Berlin to seventh place, he made sliding, spectacular blocks and tackles look routine. But for everyone else, last night marked a pivotal moment in our budding acquaintance with the 23-year-old – and with the next generation of national team talent he represents.

Brooks, like Jermaine Jones, was born and grew up in Germany; his childhood world was post-reunification Berlin. The Hertha defender played for both German and US youth teams when he was a teenager. Given the depth of playing talent in Germany it’s no surprise he eventually pledged his national playing allegiance to the USMNT, and while there’s no question about his eligibility to play for the US, it takes time for players in Brooks’s position – brought up in a different country and unfamiliar to the domestic US football public – to cement their place in the national footballing consciousness. After last night, consider the cementing done.

The players closest to Brooks also made decisive contributions. Geoff Cameron provided able support by Brooks’s side, and Brad Guzan pulled off a string of saves to deny certain goals. Cameron grew up in Attleboro, a small town in southern Massachusetts that’s closer in spirit to Rhode Island, which it adjoins, than the state it nominally belongs to. Attleboro, like Fall River and some of the other towns nearby, is hardly the most exciting place in the country. Sure, it’s not exactly the Rust Belt, either; this isn’t the hardscrabble America of Scrappy Joe Biden’s Scranton. But there’s something damp and vaguely sinister about the place, and it’s hard not to see a bit of hard town Massachusetts in the saturnine, no-bullshit toughness that defines Cameron’s manner both on and off the field.

Guzan, by contrast, is a Polish kid from the middle-class suburbs of Chicago’s south-west. Watching him in action can be unnerving, because he doesn’t look much like a goalkeeper at all. Relaxed, clean-pated, radiating a sense of affluence and easy confidence, Guzan to me looks more like a dentist from the Upper East Side named Julian who enjoys brunch at Atlantic Grill, plays bass in a roots band, and follows a strict, white pants-only dress code on summer weekends. Every time he gets the ball in his hands, you half-expect him to hold the play up, turn to his back four, and say: “Guys, are we ready for refreshments yet? Let’s open a bottle of rosé.” This is a dapper, calming quality it’s perhaps no bad thing for a goalkeeper to project. It’s also a useful point of contrast to the other players by Guzan’s side, whose chief strengths are timing and anticipation (Brooks) and sheer brawn (Cameron): the case for the defense is also, curiously, a case for diversity.

Six days ago there was still a good chance Klinsmann would be fired by the end of this tournament. Today the US enter the quarter-finals as the top team in their group, flush with belief after two victories of divergent but complementary qualities. If Klinsmann’s world has gone from storm clouds to sunshine in the space of a week, it’s down, in large part, to the efforts of this accidental trio. Brooks, Cameron, and Guzan, the Berliner, the New Englander, and the Upper East Side dentist: the US’s back three is now as unmovable as it once, perhaps, was unlikely.