In a thrilling encounter, Elvis Patta scored an 80th-minute winner to see Universidad Catolica past Independiente del Valle 4-3.
With Olmedo held to a 0-0 draw by Deportivo Quito, the win lifted Catolica level on points with the league leaders, but they remain behind on goal difference.
Emelec hold the only perfect record in the league as a 3-0 win over Deportivo Cuenca made it two from two.
Denis Stracqualursi, Miller Bolanos and Marcos Mondaini scored for Emelec but the Guayaquil-based club remain behind Olmedo and Catolica, having played one less game this season.
Catolica fell behind at home to Independiente on 10 minutes as Andi Caicedo scrambled home from a corner.
The equaliser was a stunner courtesy of Facundo Martinez just 11 minutes later.
Receiving the ball 35 yards from goal, Martinez unleashed a right-footed rocket into the top corner.
Diego Benitez put the hosts ahead for the first time on 27 minutes as he poked in from close range before Jonathan Gonzalez equalised just before half-time when he tapped in.
The goals continued to flow in the second half as Catolica restored their lead through Armando Wila, who used his strength to turn his marker before firing into the bottom corner.
Daniel Angulo drew the visitors level on 78 minutes but Patta had the final say when he got free at the back post to score the winner.
On Saturday, Olmedo failed to find a way through at home to Deportivo Quito, who are yet to score in two games this season and collected their first point.
LDU Loja and Barcelona played out a 1-1 draw, Mushuc Runa and Manta drew 1-1 and LDU Quito edged El Nacional 1-0.
