“We had to fall into the mud,” a lifelong fan of River Plate said about the team’s relegation. “We had to begin again.” PHOTOGRAPH BY AMILCAR ORFALI/LATIN CONTENT/GETTY

In 2011, after a series of dismal seasons, River Plate—Argentina’s most successful soccer club, winner of more than thirty national championships—was relegated to the second division, the B league. There’s no analogous situation in American sports, but for a sense of scale imagine the New York Yankees playing so poorly that they were dropped to the minor leagues. Cue rending of garments.

There are a lot of things Argentines do better than most—beef, red wine, conspiratorial politics. I’d add raw, sports-related emotion to the list. Take, as proof, Atilio Costa Febre, the voice of River Plate for the Buenos Aires station Radio Mitre, who spent the last twenty minutes of that decisive, losing match in 2011 cursing the team’s board of directors live on the air. “They fucked us!” he shouted into the open microphone. “Rats! Thieves! Where is the money you stole?” He was referring to the money made from selling the team’s talented prospects off to Europe. When my audio program, Radio Ambulante, interviewed Costa Febre several weeks after his remarkable tirade, he still hadn’t recovered. He called River Plate’s relegation “one of the fifty most important cultural events in Argentine history.”

And I suppose he could be right. I’m teaching in Buenos Aires this week, and for the past four days I’ve noticed the taunting graffiti all over the city, River spelled with a “B.” In fact, it’s there, on a wall across from the building where our classes are being held: “RiBer, Putos, Te Vamos a Matar.” (Roughly: RiBer, fuckers, we’re going to kill you.)

I’d wager any dollar amount (at any of the myriad black-market exchange rates available here in Argentina) that the poet who wrote this line is a fan of River Plate’s historic crosstown rival, Boca Juniors. Last night, the two teams met, a so-called Súper-Clásico, their first encounter in a Copa Libertadores since River returned to the first division, in 2012. Libertadores is South America’s most prestigious annual club competition, and Boca and River had both reached the round of sixteen. Tickets to the match were being resold for three thousand dollars. I went with Diego Erlan, a local journalist and lifelong River Plate fan, whose brother works for the club. Diego, like many fans I’ve talked to this week, told me that, while dropping to the B was a blow he’d never expected, relegation had revived his love for the team. “We had to fall into the mud,” he said. “We had to begin again.” And they did. In the three months after the debacle, the club signed up ten thousand new paying members. (Many soccer clubs in Latin America, as in Europe, are associations: while anyone can pay to go to the stadium, members have special privileges, and vote for the directors who run the clubs.)

River spent only a year in the B, but it was a hard year: playing against rough provincial teams dying to beat the legendary squad from the capital; in miserable stadiums, worlds away from River’s Estadio Monumental, a behemoth built to hold more than sixty thousand fans. Still, they survived and won the B, earning a promotion back to the first division. Last year, they were crowned Argentine champions, possibly the most cathartic title in the history of Latin American soccer.

But Libertadores is special; it has the prestige of the Champions League, and just as much history. River has reached the final four times, winning the coveted trophy twice, in 1986 and again in 1996. To get to last night’s match, Diego and I crossed the entire city, a bus to a train to another train, and then a half-hour walk, the crowds growing as we approached Estadio Monumental, until I felt I was being pulled along by a force greater than myself. I love walks like this, the last leg of a long journey to a soccer stadium; you take purposeful, determined, anxious steps, and you take them first as an individual, until, almost without noticing it, something changes, and you’re walking as part of a collective. There is singing. There is clapping. There is joy and nervousness. You walk in a rhythm and sing to ease the tension. I’m Peruvian, and, for me, it’s easy to support River: their jersey is similar to our national-team uniform, and I have a soft spot for teams in red and white. If I’d known the songs, I would have sung them.

As a spectacle, the match did not disappoint. There are no away fans allowed in Argentine stadiums, a measure enacted by the Argentine Football Association in 2013, after a Lanús supporter was killed in clashes after a match against Independiente. To see El Monumental as a unified sea of red and white was extraordinary. The singing and drumming never stopped. Old men smoked nervously for ninety minutes. I heard well-known vulgarities combined in new and surprising ways. And when River Plate’s goal arrived, from a questionable late penalty, the stadium exploded in full-throated joy.

Next Thursday, the two rivals face each other again. River Plate needs only to tie or lose by a single goal, and it is through to the next round. Nothing would feel better to the fans than knocking Boca out of Libertadores—and nothing would demonstrate so thoroughly that the club is well and truly back.