The most daunting question about Spain, as they prepare to face Germany, was put on display by Paraguay as the resolute South Americans effectively stonewalled La Furia Roja for most of 90 minutes. Switzerland, Paraguay, and to an extent Portugal have all raised the same specter: that discipline in strategy may well be the key to unraveling the skillful and improvisational passing orgy of the World Cup favorites.

That Spain has come out of a few games Indiana Jones-style, barely ducking disaster, and lost to a mediocre team in the group phase becomes all the more nerve-racking when one considers the idiom of the Deutschland squad. Germany has perfected the art of ruthless efficiency in all walks of life—the trains run on time, the cars don’t break, and the soccer team is far, far greater than the sum of its parts. This team may not have the virtuosity or artistry of Spain, but whatever they do, they do it like clockwork.

Spain, on the other hand, seems to play incredibly, mesmerizingly, fluidly—when they feel like it. Wednesday will be the ultimate battle between consistency and potential.

Paraguay’s first bold move came before the match, with Gerardo Martino fielding a completely different lineup from the one that held off Japan. This may have been a matter of tactical thinking, but it was just as likely a matter of fitness—the freshness of players who didn’t recently spend over two hours fighting blue samurai was a factor.

Del Bosque meanwhile didn’t want to fix what wasn’t broken, leaving the side unchanged. This included sweet, struggling Fernando Torres, whose first goal in this World Cup will be downright ejaculatory if it ever occurs.

The Paraguayans approached the game like a pack of rabid hyenas, feverishly attacking and harassing every Spaniard in sight. It was spirited bordering on desperate, and it seemed unsustainable, but a vicious shot on goal from Jonathan Santana before the 1–minute mark was enough to raise an eyebrow. Spain, meanwhile, was patient bordering on complacent, allowing the South Americans to tear around the pitch and hoping they would punch themselves out.

The Paraguayan pace didn’t hold up for the whole half, but their attempt to become a team of Park Ji-Sungs did keep Spain largely on their heels, if calmly so. Xavi managed one dangerous ball that looked to have keeper Justo Villar defeated, only to go over the crossbar. Other than that, the man who looked most likely to break through at any given moment was Paraguay’s Nelson Valdez, whose hustle was almost as awesome as his hair.

The famous Spanish rhythm was soundly disrupted. Spanish passes were occasionally terrible, control of the ball was sloppy at best, and at times it seemed as if the entire team just needed a nap. Del Bosque’s side spent the first half sluggishly keeping the enemy at bay, looking like sleep-deprived parents being pestered by their Paraguayan children at 5 AM on Christmas morning.

And then came the 41st minute, in which Paraguay scored. Sort of. Valdez broke at the right moment to receive a long ball in, hammering it home. But he was whistled offside, to the rage of many millions of viewers who still remain convinced that Valdez was on. The call was one of two from this game that will occupy a place in this tournament’s list of controversies.

With Torre’s efforts remaining unproductive, the ridiculously underutilized Cesc Fabregas found himself called on in the 56th minute, to positive if unremarkable effect. A minute after the substitution, Gerard Pique pulled Oscar Cardozo down in the box for a clear-cut penalty. It seemed like the energy of Paraguay was sure to pay off, but Saint Iker was magnetized to the well-taken shot, diving superbly to his left and eating the blast.

Two minutes after that, David Villa was breaking for goal with no one in his way. Antolin Alcaraz hit Villa from behind, shoving him into the pitch and earning Spain the PK. Xabi Alonso stepped up to bury the shot, but to the rage of a few more millions of viewers, the goal was discounted for encroachment. Alonso took another stab, but this time Villar wrapped it up. The frustration mounted, and as Spain mustered their efforts, their foes closed down defensively. With most of the Paraguayans behind the ball, it seemed as if the Spanish could only beat themselves against a red and white wall for the rest of the half.

Andres Iniesta would change all that. In the 83rd minute, his breakaway drew three defenders his way. With his quick pass to Pedro, it seemed like a goal on a platter. Unfortunately, Pedro pinged the post, and as the ball ricocheted back into the box, a certain special someone was there to finish the job.

You guessed it: David Villa hit the rebound, which pinballed between both posts before landing in the goal. Spain was in the lead, as was Villa in his race to win this tournament’s Golden Boot.

The final drama would come with a Paraguayan breakaway that had Casillas heroically blocking both a blast from Barrios and a follow up from Santa Cruz, reminding us all of the reason for his canonization. A rapid counterattack saw Villa denied by Villar.

And now we move to the semis, where Spain hopes to repeat their triumph over Germany in the Euro 2008 final, and Germany hopes that their record can remain as consistent as their play.