Well, Thursday night turned South American soccer on its entire head. Heading into the second-to-last matchday, we thought we knew everything about CONMEBOL World Cup Qualifying. The only remaining drama was whether Argentina would get its shit together, or whether Peru and Chile would sneak into Russia 2018 over the Albiceleste. 24 hours later, thanks to Paraguay’s last-gasp winner against Colombia, mayhem rules over the most competitive qualifying region in the world. How did we get here?

It all starts with Paraguay. La Albiroja was down 1-0 to Colombia in Barranquilla, after Radamel Falcao slotted one home in the 79th minute; it sure looked like Paraguay would be out of qualifying and Colombia would waltz in with no worries heading into the last matchday. That all went to hell, however, in the 89th minute, when veteran striker and terrifying human Óscar Cardozo equalized for the Paraguayans, before a last-gasp 92th minute goal by 21-year-old Betis striker Antonio Sanabria turned a 3-team race for 2 slots into a 5-team mad scramble for 3 positions.

That’s because Argentina failed to conquer its qualifying demons at La Bombonera; whether due to Peru’s staunch defensive performance and goalkeeper Pedro Gallese’s Herculean effort, or by just simple bad luck–Argentina’s vaunted attack should have put at least 3 goals past the Peruvians, but goalposts and barely overhit headers intervened–the Albiceleste could not grab 3 valuable points from their closest rivals, settling for one of the day’s three 0-0 draws, which sees them enter the final matchday in 6th place, thanks to what happened in Santiago, Chile.

For a brief moment, it looked like Chile’s fight to stay in the World Cup was going to make a massive hit. Despite leading most of the game, La Roja gave up a goal to Ecuador’s Romario Ibarra Mina in the 84th minute, dropping them into sixth on the up-to-the-minute standings. With a tough away fixture in Brazil coming up as their qualifying finale, it seemed that Chile might be over and dusted, but despite being one of the older teams in the region, they still have Alexis Sánchez. The (for now) Arsenal star saved his country’s skin with an 85th minute goal, and the mayhem in Barranquilla bumped Chile from the no qualification zone all the way up to 3rd in the region. A draw against the Brazilians–who theoretically have nothing to play for except their “Brazil has never lost at home in qualifying” record–should be enough to secure Chile a spot in Russia.

That’s how we stand heading into the final round of games, one that promises to have fans reaching for their phones to make sense of the real-time scenarios for qualification. Four of the aforementioned five teams–Argentina, Peru, Colombia, and Chile–control their own destiny; a win and they are, at the very least, in the continental playoff spot. Paraguay needs to win their home match against last-place Venezuela, along with a few results to go their way in the other games, in order to have a chance to stay alive.

The Peru-Colombia match in Lima looms as the most important showdown in Matchday 18; both teams could qualify with a draw, but it’s unlikely that both will qualify if there’s a clear winner. Peru could ride their recent hot streak to their first World Cup in 36 years, while Colombia could overcome the meltdown against Paraguay to secure a spot that seemed so certain just 24 hours ago. Don’t overlook the Argentina-Ecuador match, either; while Argentina has everything to play for and Ecuador just has their pride, the game is in Quito, whose high altitude gives opponents almost as many problems as Bolivia’s La Paz stadium. Argentina hasn’t scored in their last 76 shots in qualifying (their only goal since Matchday 13 was an own goal from Venezuela), and their attacking impotence might cost them against La Tricolor of Ecuador.

It’s here that we must acknowledge how insane it is that so many talented South American teams compete for only 4.5 slots in the World Cup. Despite all 10 teams in the region being ranked in the top 68 of the FIFA rankings, only half–at most–will participate in soccer’s biggest tournament, due to the ridiculous layout of qualifying. While European powerhouses are generally put into groups with one or two difficult opponents and a handful of minnows, the ten nations of CONMEBOL participate in a grueling 18-match round robin that features some of the most physically intense soccer in the world. Could Venezuela, who has never reached a World Cup, qualify if they were put in a group with Luxembourg and San Marino, instead of having to play the Brazils and Uruguays of the region? We’re not going to say “definitely,” but “probably” feels fitting.

This problem will be somewhat alleviated when the World Cup expands to 48 teams in 2026, as CONMEBOL will get a full 6 slots in that tournament, but the point remains the same: 4 teams will not make it to the World Cup, while European mid-card teams like Northern Ireland and Scotland will qualify with ease. While that does make South America the most hotly-contested qualifying region–and perhaps the only exception to soccer fans’ dislike of the international breaks–it also will leave at least two deserving teams home from Russia 2018. Could it be Peru, with their fantastic second half run and back-and-forth matches? Or Chile, with all their experience and grit? Could Colombia, the darlings of the 2014 World Cup, be left out? Or will it be Argentina and Lionel Messi that don’t get a chance to repeat their World Cup final performance next summer?

Whatever the case, the difficulty of qualifying out of CONMEBOL will weigh heavily on these teams as they lace up for Tuesday’s decisive matches.