GUADALAJARA, Mexico -- Chivas and Club Tijuana advanced to the semifinals of the 2017 Clausura with quarterfinal victories on Sunday.
The wins mean that Chivas will play Toluca in the semifinal, with Tijuana facing reigning champions Tigres. The first legs are scheduled for Wednesday and Thursday, with the return fixtures next weekend.
Chivas' Orbelin Pineda scored the only goal of the encounter against Atlas on the stroke of half-time, deflecting a Oswaldo Alanis header past Atlas keeper Miguel Fraga.
The aggregate score was 1-1 over the 180 minutes, but Chivas advanced due to finishing higher up in the regular season.
Chivas attacked right from the start and striker Alan Pulido had the ball in the net within a minute, but it was ruled out for offside. TV replays showed it was a marginal decision.
Atlas had set up to defend the one-goal advantage from the first leg and coach Jose Guadalupe Cruz left star striker Matias Alustiza on the bench, bringing him on at half-time as Atlas moved from a 5-4-1 to a 4-4-2 formation. Cruz later said Alustiza had been carrying a minor injury.
Atlas went close on a couple of occasions, but it was Chivas who had the better chances in the second half, with Pulido forcing a good save from Fraga and Rodolfo Pizarro hitting the post.
Chivas are bidding to win their first Liga MX title in over a decade and came into Sunday's match without a victory in their last six games.
In Club Tijuana's victory, Henry Martin scored three minutes before half-time and Juan Lucero got the second in the 80th to propel the regular season first-place finishers to the semifinal.
In Saturday's quarterfinals, Tigres advanced past city rivals Monterrey, while Toluca overcame Santos Laguna 5-4 on aggregate.