The Primera A's top three are unbeaten but have been far from dominant, with Emelec sitting third and holding a game in hand with two wins in three.
There were four draws in six matches in the fourth round but LDU Loja were not among them after a 1-0 win at Mushuc Runa.
A fine team move led to the only goal of the game at the Estadio Bellavista and Jonny Uchuari finished off.
Newly promoted Mushuc Runa have made a rough start in the top flight, bottom with just one point.
Olmedo came from behind at Deportivo Cuenca on Sunday to ensure they stayed top after a 1-1 draw.
Juan Manuel Cobelli capitalised on a fortuitous rebound to open the scoring for the hosts with the outside of his left foot in the 25th minute.
Edwin Caicedo equalised on 67 minutes with a tremendous strike.
The midfielder unleashed a stunning 35-yard rocket, which smashed into the top corner to earn Olmedo a point.
El Nacional were the only team to join LDU Loja on the winners' list as they upset Universidad Catolica 2-1 for their first victory of the season.
Manta scored a dramatic late equaliser in a 1-1 draw at Deportivo Quito, while Barcelona and LDU Quito drew 0-0 and Independiente del Valle versus Emelec also finished scoreless.
