Colombia's Darwin Quintero scored twice in the second half to earn Santos Laguna a 3-1 victory over Atlas on Sunday and a spot in the semifinals of the Mexican playoffs against Cruz Azul, which advanced despite losing 1-0 to Morelia.
America plays Monterrey in the other semifinal after it overcame Pumas 2-1, and Monterrey drew 1-1 against Tigres - both on Saturday.
The semifinal first legs are scheduled to take place on Wednesday and Thursday.
Atlas opened the scoring in the 4th minute when Omar Bravo shot from a tight angle, with TV replays showing there was doubt over whether it did cross the line.
Colombian Andres Renteria took advantage of a mix-up in the Atlas defense in the 16th to equalize for Santos Laguna.
Atlas goalkeeper Miguel Pinto was sent off in the 24th for handling the ball outside the area, with Quintero then scoring from close range in the 62nd after Renteria crossed for an easy opportunity and Quintero added his second in the last minute.
The first leg had finished in a 0-0 draw Thursday.
Rodrigo Salinas struck a fierce shot from the edge of the area for Morelia's only goal one minute before halftime.
Morelia increased the pressure in the second half looking for the goal to send it through, but Cruz Azul, which advanced on aggregate after winning the first leg 4-2, resolutely held on.
Ecuadoran striker Christian Benitez netted twice for America, which came into the game after winning the first leg 1-0.
Robin Ramirez opened the scoring for Pumas with a left foot shot into the top left corner of the net from the edge of the penalty area in the 21st.
Monterrey's equalizer came under strange circumstances, when Tigres' Israel Jimenez sliced a clearance from outside the penalty area that sailed over `keeper Enrique Palos and into the net in the 33rd.
Brazilian Danilinho had given Tigres the lead when he chested down a long ball and fired the ball into the net in the 12th. He was sent off in 79th for his second yellow card.
The first game between the two last Wednesday had ended 1-0 to Monterrey.
