River was better planted at the beginning of the game and generated the first chances of goal with a header from Lucas Pratto, after Rafael Borre's center, which was close to Nereo Fernandez's left post. Then, Juan Quintero tried from outside in a good individual maneuver but the ball went just over the crossbar.
Union responded with an approach by Augusto Lotti which Gonzalo Montiel managed with just enough. The defender himself had a header that passed near the right post of Union and then came the opening of the scoreboard: Kevin Sibille committed a controversial penalty on Franco Troyansky and Franco Fragapane scored the first goal, when River was clearly superior and dominated the game.
In the closing of the first half, Montiel stormed to the right after Quintero's pass and touched back for Pratto, but the striker could not hit the ball fully, in what would have been the draw before the end of the first half.
River struggled in the second half, but still maintained control in the rival field. They were unable to generate danger until the first moves arrived at the feet of Exequiel Palacios, with a high shot from outside the area, and a situation of Borre, who managed to hit the ball with just enough and went near the right post of Fernandez.
Union found the second one in the only play they had, with a shot by Diego Zabala after a play by Nelson Acevedo on the left side. At the end, Quintero shot from the outside, Jonathan Bottinelli deflected the ball and River scored the discount, but he ran out of time to achieve a draw.
Thus, "El Millonario" missed the opportunity and will now wait for the next match, which will be this Sunday against Patronato, also in the Monumental Stadium.
RIVER PLATE: Franco Armani; Gonzalo Montiel, Kevin Sibille, Javier Pinola (C), Milton Casco; Enzo Pérez, Ignacio Fernández, Exequiel Palacios; Juan Quintero; Lucas Pratto and Rafael Borré. DT: Marcelo Gallardo.
Substitutes: Germán Lux, Robert Rojas, Camilo Mayada, Bruno Zuculini, Cristian Ferreira, Nicolás De La Cruz and Lucas Beltrán.
Changes: Mayada for Montiel, De La Cruz for Fernández, Ferreira for Pérez.
UNIÓN: Nereo Fernández (C); Damián Martínez, Yeimar Gómez Andrade, Claudio Corvalán, Bruno Pittón; Diego Zabala, Nelson Acevedo, Mauro Pittón; Franco Fragapane; Franco Troyansky and Augusto Lotti. DT: Leonardo Madelón.
Substitutes: Marcos Peano, Jonathan Bottinelli, Santiago Zurbriggen, Matías García, Lucas Ríos, Nicolás Mazzola and Maximiliano Cuadra.
Changes: Cuadra for Lotti, Bottinelli for Troyansky, Rios for Zabala.
Goals: Quintero (RP); Fragapane, Zabala (U).
Admonished: Fernández, Sibille, Ferreira (RP); Fernández, Fragapane (U).
Referee: Nicolás Lamolina.
Attendees: Javier Uziga and Diego Verlota.
Fourth referee: Lucas Novelli.