QUITO, Aug. 21 (Xinhua) -- Reigning champion Botafogo was knocked out of the Copa Libertadores on Thursday after a 2-0 defeat to Ecuador's LDU Quito in their round-of-16 second leg.

Gabriel Villamil opened the scoring in the seventh minute after being set up by Lisandro Alzugaray, who later converted a 60th-minute penalty to overturn Botafogo's 1-0 advantage from the first leg in Rio de Janeiro.

LDU finished with 10 men after Richard Mina was sent off for a dangerous challenge on Jeffinho with 10 minutes remaining, but the host held firm to advance 2-1 on aggregate.

"The first game in Brazil was decisive for today," LDU manager Tiago Nunes told a post-match news conference. "We're a competitive team and we knew we had the potential to come back at home. I was sure we'd put in a great performance. This is a source of great pride."

In Buenos Aires, Franco Armani saved the decisive penalty as Argentine side River Plate beat Paraguay's Libertad 3-1 in a shootout.

After a goalless first leg in Asuncion, River went ahead through Sebastian Driussi's close-range header before Robert Rojas equalized on the stroke of halftime.

The host played most of the second half with 10 men after Giuliano Galoppo was dismissed for a second booking.

River resisted waves of pressure to take the match to penalties, with Nacho Fernandez, Miguel Borja and Lucas Martinez Quarta all converting.

Armani then dived left to deny Marcelo Fernandez, sealing victory after Hernesto Caballero and Jorge Recalde had already missed for the visitor.

In Thursday's only other round-of-16 fixture, Palmeiras drew 0-0 at home against Universitario, giving the Brazilian side a 4-0 win on aggregate. ■