Peruvian side Cienciano and Paraguay's Cerro Porteno have qualified for the Copa Sudamericana's last 16, after eliminating Uruguay's Liverpool and Bolivia's La Paz in their preliminary stage ties.

Cienciano, who won this tournament in 2003, beat Liverpool 2-0 at home after last week's goalless draw in Uruguay. Cristian Guevara in the first half and an own goal by Carlos Santucho gave the Peruvians qualification.

In Bolivia, Cerro Porteno claimed a 2-1 victory for a 4-1 aggregate win. An early goal by Argentinian striker Roberto Nani gave the Paraguayans a momentum which La Paz could not reverse.

Indeed, Julio dos Santos widened the gap to put Cerro four goals ahead on aggregate before Ronald Segovia hit a consolation for the Bolivians early in the second half.

Finally, in the first leg of the all-Argentinian duel, two-times Copa Sudamericana champions Boca Juniors could only manage a 1-1 home draw against Argentinian champions Velez Sarsfield.

Boca got an early advantage thanks to a goal by Pablo Mouche only two minutes in and were dominant during the first half. But Velez improved as the game wore on and an own goal by defender Gabriel Paletta 11 minutes from time levelled the scores.