By Michael Place

PORTO ALEGRE, Oct. 30 (Xinhua) -- Argentina's River Plate secured a place in the Copa Libertadores final on Tuesday by recovering from a two-goal deficit to beat defending champions Gremio of Brazil on away goals.

Gonzalo Martinez converted a late penalty to earn the visitors a 2-1 victory in the semifinal second leg at Arena do Gremio after the Brazilian side won last week's first match in Buenos Aires 1-0.

River will now face the winner of the other semifinal between their traditional rivals Boca Juniors and Brazil's Palmeiras. Boca will take a 2-0 advantage into Wednesday's deciding leg in Sao Paulo.

"We showed a lot of courage and personality to play the way we did and never give up," a jubilant Martinez said after the match. "This is a great group and the result is well deserved."

Leonardo Gomes gave the hosts what appeared to be an unassailable 2-0 lead by blasting in a low shot from outside the box in the 35th minute.

But River gave themselves a chance when Santo Borre headed in after a Martinez set piece.

As is so often the case in Copa Libertadores knockout stages, the final minutes of the match were marked by drama and controversy.

Ignacio Scocco's 84th-minute shot was blocked by Matheus Bressan's outstretched left hand and referee Andres Cunha did not hesitate to consult the video assistant referee.

After a delay of more than 10 minutes, Cunha awarded a penalty to River and dismissed Bressan for a deliberate handball.

The decision prompted chaotic scenes as Bressan and several of his teammates remonstrated with Cunha and his assistants.

When order was finally restored Martinez held his nerve by firing his spot-kick into the top left corner of Marcelo Grohe's goal.