BUENOS AIRES, (Reuters) -- Striker Santiago "Tank" Silva scored twice as Argentina's Velez Sarsfield won 3-0 at Caracas FC to qualify for the Libertadores Cup knockout phase on Thursday.

Universidad Catolica beat fellow Chilean side Union Espanola 2-1 to go through as Group Four winners one point ahead of Velez, while Caracas missed out after starting the game as group leaders.

Santos, minus suspended Brazil internationals Neymar and Elano, kept alive their hopes of going through in next week's final matches in Group Five when they beat Cerro Porteno of Paraguay 2-1 in Asuncion.

At the Olimpico in Caracas, midfielder Maxi Moralez put 1994 champions Velez ahead in the 20th minute when he scored from Juan Manuel Martinez's cross.

Uruguayan Silva then scored twice in eight minutes early in the second half to settle the game, his first either a remarkable piece of skill or benefiting from a huge slice of luck.

Out by the left touchline and near the goalline, Silva appeared to cross the ball into the box, but it flew over the head of goalkeeper Renny Vega and in off the far post.

The burly, shaven-headed Uruguayan scored again with a diving header from midfielder Ricky Alvarez.

"It's a long trip to get here (to Venezuela), the pitch was not in a good state and we played against a team that play good football," man of the match Silva told Fox Sports.

Velez substitute Gaston Diaz was sent off five minutes from time for a second booking.

Santos began their match in third place in Group Five, four points behind second-placed Cerro Porteno, but made light of the absence of three players, including Ze Eduardo, sent off in last week's home win over Colo Colo of Chile.

Colo Colo lead with nine points, one more than Cerro Porteno and Santos with the Paraguayan side second on goal difference.

Midfielder Danilo put Santos ahead after 11 minutes and substitute striker Maikon increased their lead less than two minutes into the second half. Pedro Benitez scored a late consolation for the previously unbeaten home side.

Teams to have qualified so far for the last 16 also include former champions Cruzeiro, Estudiantes, LDU Quito, Penarol and Gremio, Colombia's Atletico Junior and Libertad of Paraguay.

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