Corinthians' early exit shows the unpredictability of the Copa Libertadores

The big guns of Europe prepare for battle next week when the knockout phase of the Champions League gets underway. The world's best will be on show -- but for all the quality, the competition comes under some fire for being increasingly predictable, dominated by a handful of super clubs.

In South America, meanwhile, the equivalent tournament, the Copa Libertadores, is still in its qualifying rounds -- and a giant has already fallen. At the first hurdle, 2012 champions Corinthians of Brazil were knocked out by Guarani of Paraguay.

This is an extraordinary development -- all the more so, because it repeats what happened in 2015, when Guarani won home and away when the sides met in the knockout stage. This time their encounter came earlier and was closer. The aggregate score was 2-2, with Guarani going through on the away goals rule. Even so, it still beggars belief.

Corinthians are the biggest team in the biggest city of South America. Greater Sao Paulo has a population of around 22 million -- three times bigger than all of Paraguay, and Guarani are by no means the biggest club in their country. The traditional top two are Olimpia (currently signing Emmanuel Adebayor to team up with Roque Santa Cruz) and Cerro Porteno, who on Wednesday night successfully negotiated their passage into the final qualifying round. Then there is Libertad, who have grown into a respectable force in the current century, and then come Guarani. Mighty Corinthians, then, have been eliminated by the fourth-biggest side in Paraguayan football. How on earth could this have happened?

One reason is that Corinthians are operating below their potential, paying the price for living out a dream. For decade after decade they used the municipal Pacaembu stadium in the centre of town while dreaming of having their own stadium. The 2014 World Cup turned that dream into a reality. Made especially for the tournament, a shining new stadium was built in Itaquera, in the east zone of the city, and Corinthians took it over once the circus left town. It is impressive -- but now Corinthians have to pay for it, and the business model has not proved effective. As it stands, the new home is something of a financial burden, preventing Corinthians from assembling a squad to match the likes of Flamengo of Rio de Janeiro and historical local rivals Palmeiras.

Another explanation is the legendary resilience of the Paraguayans, never happier than when they can fall back and defend with a unique combination of cool and desperation. Guarani won last week's home leg while enjoying less than 30% possession and that is exactly how they wanted it. They scored early and then dedicated themselves to preventing Corinthians from scoring an away goal.

In Sao Paulo, they defended doggedly, but in little spurts they attacked aggressively when they could -- and when they had to. They found themselves two goals down before half-time but responded with excellent substitutions, and a vital goal early in the second half. Big centre-forward Fernando Fernandez -- who scored the only goal in the same venue back in 2015 -- battered home a free kick from the edge of the area, following a period of sustained pressure when Corinthians' defence was in real trouble.

By this time the Brazilians were down to 10 men, as attacking midfielder Pedrinho had been sent off just before the half-hour mark in a harsh decision. The second yellow came after he made a genuine attempt to play an overhead kick, when common sense would have suggested the referee should have let him off with a warning. But the Brazilians' many protestations against the refereeing floundered on one clear fact. For the last 11 minutes Guarani were also down to 10 -- and the red card awarded to centre-back Jhohan Romana was even harsher. The big Colombian -- a serious contender for man of the match award -- appeared to have done little wrong when he picked up his second yellow card. Perhaps Argentine referee Nestor Pitana, who handled the last World Cup final, was subconsciously compensating for giving Pedrinho his marching orders.

More of a factor in the result than the refereeing was the lack of calm showed by Corinthians -- right from the early minutes when they were flying into rash challenges. They were too aware of the importance of the occasion. The pressure of being the favourites, the possibility of a humiliating early exit, the need to chase the game -- all clouded their minds and worked in favour of the underdogs.

It all produced a gripping spectacle, and further proof of the capacity of the Copa Libertadores to come up with the unpredictable.