This year's Copa Libertadores final, between Boca Juniors and Corinthians, is a truly heavyweight clash. On and off the pitch, the two combatants are giants of South American football. They are both current national champions and hold 28 league titles and four national cup titles between them. They are the most popular clubs in their respective megacities, beloved for their working-class roots, and count their supporters in the tens of millions.

But when it comes to continental competitions, their records are very different. Boca, Argentina's most celebrated club, have won the Libertadores six times, the Copa Sudamericana (the equivalent of the Europa League) twice, the Recopa (South America's Super Cup) four times and the now-defunct Intercontinental Cup three times. Corinthians, on the other hand, have had next to no success internationally. Their only victory on the world stage came in the inaugural Club World Cup in 2000, for which they qualified by hosting the tournament.

Boca are defined by their success in the Libertadores. This year's final is the club's tenth, equalling the record of Uruguayan side Peñarol, who competed in five finals in the '60s (and lost to Santos in the 2011 edition). Boca have made it to five of the last 12 finals, winning the tournament back-to-back in 2000 and 2001. If they are victorious over the two legs of this year's final, which starts on 27 June, they will join Independiente on seven titles and become the most successful team in the tournament's history.

Corinthians, for all their domestic success, have found the Libertadores particularly elusive. In fact, they have never before made it this far. Unsurprisingly, the competition has become something of a bugbear for the club – made worse by the knowledge their rivals Palmeiras, São Paolo and Santos have all won it at least once.

Unsurprisingly, continental football in South America is dominated by clubs from Brazil and Argentina. Argentinian clubs have accumulated the greatest number of victories in the Copa Libertadores, 22, while Brazil has supplied the most individual winners, eight. This year's final is the 13th Brazil v Argentina clash, with Argentina up 9-3.

Despite this dominance, Boca and Corinthians have only met four times in competitive fixtures – two-legged ties in the 1991 Libertadores and the 2000 Copa Mercosur. For what it's worth, Boca won on both occasions, with Corinthians failing to win any of the games. Frankly, though, it's not worth a lot – the sides that will line up this week and next are not typical of either club or, indeed, of South American football.

The campaigns of both clubs have been founded on solid defending. Corinthians manager Tite has taken the same robust, consistent approach that served them so well in the Brasileirão and applied it to the Libertadores. To say it has worked is a terrific understatement. Corinthians are unbeaten in the competition and have conceded only three goals in the whole tournament, keeping nine clean sheets in 12 games.

Boca aren't too shabby at the back either. After a shaky start in the group stage – they drew with a decidedly average Zamora team and lost to Fluminense in their opening two games – they found their rhythm, winning the rest of the group encounters and keeping seven clean sheets en route to the final.

At the other end of the pitch, no one from either side has really troubled the goalscoring chart. Pablo Mouche, Juan Román Riquelme, Santiago Silva and Juan Sánchez Minõ (a defender) lead the way for Boca with three apiece, while Corinthians leading marksman, Danilo, can only go one better. It's not that neither team has scored many goals – Corinthians bagged 13 goals in the group stage; Boca scored five in their last 16 tie with Unión Española –  but rather that they have utilised systems that play to the strengths of the whole group.

Tite favours a European-style 4-2-3-1, with the solid midfield pairing of Ralf and Paulinho stifling attacks through the middle. Boca's 4-3-1-2 also builds from the back, with three midfielders shielding the workmanlike centre back duo of Rolando Schiavi and Juan Insaurralde.

As if to test the very principle of their organised formations, Boca and Corinthians found themselves up against two of the competition's most exciting, attacking teams in the semi-finals: Universidad de Chile and Santos respectively.

Universidad de Chile – La U – have had an incredibly successful 12 months. Managed by Marcelo Bielsa disciple Jorge Sampaoli, their style is characterised by short passing, high pressing and a dynamic forward three. They won the Apertura and Clausura domestic titles in 2011 and finished the year by wrapping up the Copa Sudamericana in some style; winning every home game and going unbeaten. Striker Eduardo Vargas' 11 goals in one tournament set a new record and earned him an £11.5m move to Napoli. Brazilian newspaper Globo Esporte was impressed enough to call the team “South America's Barcelona”.

But La U's intense schedule of 75 competitive games in a year caught up with them, and they were slow out the blocks in the first leg of the semi-final in Buenos Aires. The Argentinians set out to take advantage of La U's fatigue, pressing them with more urgency than usual and forcing errors. The opening goal came from a poor touch by Charles Aránguiz which allowed Mouche to intercept, peg it down the right and cross for Silva; the second was the result of Boca's adventurous approach, with Riquelme pouncing on a mistake deep in the opposition half and taking out central back Osvaldo González and right midfielder Matías Rodríguez with a superb pass for Sánchez Miño.

All of which meant Boca took a fairly comfortable 2-0 lead into the second leg. La U went hell for leather, playing 4-3-3 and pushing up their full backs. Not surprisingly, it left holes. Riquelme hit the bar after eight minutes and Boca could have been 4-0 up at half time, were it not for the profligacy of Mouche and Silva. Boca's attacking play created chances for La U too – playmaker Marcelo Díaz and Raúl Mario Ruidíaz both hit the bar – but the deadlock was not broken. “We gave our best,” said Díaz after the game, “but we didn't lose the tie here – we failed in Buenos Aires.”

The other semi-final, the São Paolo Superclásico between Corinthians and Santos, promised to be a tasty encounter indeed. It pitted the most reliable team in Brazil against the holders of the Libertadores, whose fluid style is epitomised by the skill and flair of their wonderkid duo, Paolo Ganso and Neymar.

Corinthians approach in the first leg was simple: keep Neymar on a tight leash. The 20-year-old winger repeatedly tried to cut inside from the left, as he likes to do, but was given no ground by Ralf and Paulinho. His opportunities were limited further by the fact he was doggedly double-marked. On top of that, Cassio Ramos was superb in the Corinthians goal – his save from on-loan São Paolo (and former Arsenal) centre back Juan inside the last 10 minutes was outstanding.

Emerson Sheik's beautiful curling top-corner effort in the first half gave O Timão a crucial one-goal advantage going into the second leg, and they set up for the game with the clear intention of keeping things tight, playing without a recognised striker. But it proved impossible to contain Neymar for 180 minutes, and he gave Santos the lead in the first half with his eighth goal of the competition. It is the only goal Corinthians have conceded at home in the tournament.

But they found their composure at half time and went ahead on aggregate moments into the second half through Danilo, who poked in a cross from the right at the far post from six yards. The goal knocked the wind out of Santos. For Corinthians, it was simply a case of shutting up shop for the remaining 42 minutes, which they did with great effect.

Against Boca, though, they will need to find a different way.  Both Corinthians and Boca play reactive football based on the principle of disciplined, organised defence. It has proved effective against more typical South American teams, but when they face each other it will be a different story. Something has got to give, which is what makes this year's Libertadores final such a fascinating encounter.

Boca, who play the first leg at home, will have to take advantage of the famously boisterous atmosphere in La Bombonera. Nearly 60,000 people will fill the compact 'Chocolate Box', almost twice as many as can fit into Corinthians' Estádio do Pacaembú. “The Bombonera [factor] is real, it exists,” Tite said this week. “You need to be mature to play there. We need to have the mental strength to do it.”

But perhaps a greater advantage for Corinthians lies in the relative freshness of their squad. The Brazilian national season is only six rounds old, so Tite has enjoyed the luxury of fielding a second team in the competition in order to preserve his best players. Boca, meanwhile, have been fighting a war on two fronts, in an (ultimately fruitless) attempt to win the Argentinian Clausura. It has cost them starting centre back Juan Insaurralde, who picked up an injury in the league against Arsenal de Sarandi.

It is probably for this reason the bookies give Corinthians the edge. But the man who calls this contest – which means so much to both clubs for such different reasons – is a braver, or smarter, man than me.