BUENOS AIRES, Jul 21 (SW) - Chivas de Guadalajara welcomed back their World Cup stars on Thursday night in Argentina with a 2-1 victory over Vélez Sarsfield in the Copa Libertadores quarter-finals, sending them through on the same aggregate score.

Vélez had the first good chance when striker Mauro Zárate neatly beat the Chivas offside trap, but after chesting down the ball he hit it high of Oswaldo Sánchez's goal.

Mexico international Ramón Morales caught everyone off-guard on 11 minutes when he hit a cracking left-footed shot from over 30 yards out, but the ball just went millimeters over the top.

Both teams looked dangerous in the buildup over the first 20 minutes, but Chivas were more successful at penetrating into the area. However, defender Walter Bustamante made many nice defensive headers to keep the Mexicans at bay.

Chivas eventually won a penalty in the 26th minute when Bustamante handled in the area while trying to keep the ball from reaching Adolfo Bautista, and Mexico international Morales stepped up and sent Gastón Sessa the wrong way for a huge away goal.

Bautista nearly gave Chivas a second goal in the 54th minute with a header off of a right-wing cross, but Sessa did well to dive to his right and make the stop. But 10 minutes later, Chivas would go a man down as Diego Martínez received his second booking for a foul from behind on substitute Pablo Batalla.

It didn't seem to matter, though, as Chivas went 2-0 up in the 75th minute as Bautista hit in a shot from the left post after a flicked-on corner kick found him unmarked.

Batalla managed to get one back for Vélez six minutes later with a cracking drive from distance that left Sánchez rooted to the ground, and Leandro Somoza nearly made it 2-2 three minutes later with a curling effort from the edge of the area, but Sánchez got a hand to it.

Chivas now move on to face world champions São Paulo in the semi-finals with Internacional playing Libertad in the other tie.