Ruben Israel's in-form Barcelona were no match for fourth-placed visitors Independiente del Valle, going down 4-1 at the Estadio Monumental Isidro Romero Carbo on Sunday.
Jonathan Gonzalez scrambled in the opener in the sixth minute for the visitors and they doubled their lead before half-time.
Junior Sornoza stepped up from the penalty spot seven minutes before the break, tucking his spot-kick into the bottom corner.
Christian Suarez pulled a goal back for the hosts early in the second half, getting on the end of a fine long pass before volleying in at the back post.
But Daniel Angulo headed in on the hour mark and Fernando Guerrero also struck with a left-footed finish late on.
El Nacional, who have a game in hand, moved within five points of top after a come-from-behind 2-1 victory at Olmedo.
Alvaro Navarro had scrambled in the opener for Olmedo in the 32nd minute as they looked on track for their first win of the season.
Sloppy goalkeeping led to Miguel Parrales' equaliser in the 70th minute before Alejandro Villalva drove in the winner from inside the area.
Universidad Catolica and Manta are below Olmedo without a win.
Walter Calderon's goal saw Deportivo Quito edge Universidad Catolica 1-0 and Manta were beaten 1-0 at Deportivo Cuenca.
Third-placed LDU Quito needed a 90th-minute winner from Jonathan Ramis to overcome Emelec 2-1 and LDU Loja beat Mushuc Runa 2-1.
