The first legs for all pairings are set to keep fans on the edge of their seats. Keep track of all the games with this guide.

The time has come to separate those who made the KO stage without any real chance to win from those who can go all the way in the Copa Libertadores.

Teams from all over South America are gunning to take leads back to the return legs of their fixtures, with some clear favorites among the lot and others that, considering their current circumstances, could be out of the tournament due to shocking developments.

As usual, Boca Juniors and River Plate will be among those to be considered title contenders from Argentina. That lot will be completed by clubs such as Palmeiras, Athletico-PR, and Fluminense, who proved during the group stage they have created worthy squads to reach the defining moments.

When it comes to defending champions Flamengo, the current turmoil between the team caused by Jorge Sampaoli's shaky coaching could see their chances of success torn apart, but it remains to be seen how the players deal with their boss' complicated ways.

Now, here are the top games to keep an eye starting on Tuesday.

River Plate vs Internacional: The final game on Tuesday will feature the winners of Group B, who finished that round without a loss, and the powerful Argentine side who claimed a spot in this round as runners-up in Group D. This will be the first meeting between these teams in a defining stage of the Copa Libertadores, and to make things even more complicated to predict, both of their previous fixtures ended in similar 2-2 draws back in the 2019 edition of this tournament. Internacional's boss Eduardo Coudet has only been able to beat River Plate in one of his nine previous matches against Los Millonarios, hinting that his compatriots could be considered favorites to take the win home on Tuesday. Click on the match for more broadcast info.

Nacional vs Boca Juniors: The hosts finished the group stage as runners-up in Group B, while Boca struggled to win group F due to a slow start. Now, both clubs will look back at their history to try and find some momentum to reach the next stage. This will be the third time in which these teams lock horns in a KO stage of the Copa Libertadores, with the first being won by Nacional in 2006, and the other one being claimed by Boca ten years later. Suprisingly, both those meetings needed penalties to be sorted out, and judging by their current form, it would not be a surprise to see them reaching that final frontier to determine the winner of the ticket to the quarterfinals. Please click on the match for broadcast and streaming details.

Flamengo vs Olimpia: In a shocking turn of events, the Brazilians finished the group stage in second place of Group A, while Olimpia earned the top spot in Group H, giving them the home-field advantage for the return tie. That advantage could be crucial, mainly because Flamengo are currently involved in a tug of war between the players ant the team's staff, especially after a row between one of Jorge Sampaoli's assistants and Pedro. It is yet to be seen if that has an effect on how the Rubro-Negro perform, but if they show any flaws, this Paraguayan side is surely capable of making them pay. Flamengo teared Olimpia apart in their previous Copa Libertadores tie with a 9-2 aggregate, but their current issues make us believe this match could have a very different ending. Click on the link above for further match info and broadcast details.

Copa Libertadores - Broadcast info for all first leg games in the Round of 16