Eduardo Salvio's helped Argentina's Lanus beat giants River Plate 2-1 in the first leg of the Copa Sudamericana Preliminary Stage.

A last-gasp strike by Salvio in injury-time saw Luis Zubeldia's side to an important win as both teams look to seal a place in the round-of-16.

Former Lanus striker Cristian Fabbiani put River ahead with a long-distance shot 23 minutes into the second half.

However, Salvio was ready to become the hero at the Estadio Monumental.

He firstly equalised at the 80th before he finished off a smart counter-attacking move started by Santiago Biglieri.

Lanus will host the second leg on September 17 and Salvio told Fox Sports that his team must retain focus.

"This result is great for us because we become stronger at home. However, we must defend very well.

"I will never forget this evening. I will enjoy it a lot."

Despite the defeat, River fans celebrated the return of forward Ariel Ortega, one of the club's biggest idols, who was back from second-division side Independiente Rivadavia.