By Gabriel Pessoa

In a mere matter of days, we will know which two teams will have stamped their tickets to Santiago, Chile for the 2019 Copa Libertadores final.

On the Brazil side of the semifinal bracket, Gremio, having only mustered a draw in the first leg against Flamengo, will now have a fight for survival on their hands on Wednesday in one of the most historic soccer venues on the planet: The Maracana.

Before that though, there's the not-so-little matter of Boca Juniors' attempt to overhaul a two-goal deficit at home against arch rivals River Plate.

Boca Juniors (ARG) vs. River Plate (ARG)

Tuesday, October 22 @ 8pm ET / 5pm PT Live on beIN SPORTS

Los Millonarios made home advantage count in the first leg, treating a jubilant El Monumental crowd to a comprehensive win over their loathed cross-town rivals.

A disjointed Boca performance was punctuated by two costly defensive errors, allowing the reigning champions to record a comfortable win in a repeat of last year's final.

Two-goal cushion aside, River Plate have something else standing in their favor heading into Tuesday's showdown: recent history. The Belgrano club is currently enjoying a six-game unbeaten streak against Boca on the continental stage.

Manager Marcelo Gallardo, meanwhile, boasts the most Superclasico victories of any coach in the history of the Copa Libertadores. Rafael Borre and Ignacio Fernandez's goals at the beginning of the month took the 43-year-old's win tally against the old enemy to three.

Whether River Plate can extend their unbeaten record to seven games will depend on Boca's bouncebackability. Just to force extra time, Los Xeneizes will need to score twice against a stubborn River defense that has only allowed an average of two shots on target per game throughout the 2019 Libertadores campaign, so Ramon Abila & co. will need to be at their sharpest.

All that being said, Boca will have the power of La Bombonera to draw on, and the support of an impassioned fanbase that will be trying to inhale the ball into River's net throughout the 90 minutes of do-or-die action.

Tuesday promises to be another epic installment of one of the most engrossing sporting rivalries in world sport.