Rio de Janeiro, May 3 - First-half goals from Alecsandro and Diego Souza were enough to give Brazil's Vasco da Gama a 2-1 victory over Lanus in their Copa Libertadores round of 16 first leg.

Alecsandro opened the scoring Wednesday at Rio's Sao Januario stadium by tapping in an Eder Luis cross on 25 minutes.

Diego Souza made it 2-0, three minutes before half-time when he gained possession in the area and, with his back to goal, flicked the ball over the head of Diego Braghieri before a first-time drive into the top-right corner.

Lanus dominated the early stages of the second half and Mario Regueiro gave his team a precious away goal with a 62nd-minute strike.

The Argentinians could have equalized late on but Regueiro and substitute Teofilo Gutierrez missed great chances.

The result means Lanus only needs to win next week's return match 1-0 to advance to the quarter-finals.

In other games, former Villarreal playmaker Juan Roman Riquelme scored in Boca Juniors' 2-1 home victory over Chile's Union Espanola.

Meanwhile 10-man Corinthians held on for a 0-0 draw against Ecuador's Emelec in the coastal city of Guayaquil.