A stunning left-foot strike from Minzun Quina just after the hour mark was enough to get the home side over the line, ensuring they made it two wins from two games.
Universitario also remained undefeated, easing past Cienciano 2-0 at the Estadio Monumental.
Manuel Ruidiaz put Universitario ahead in the 37th minute, finishing off a flowing move with the simplest of finishes, before Christopher Gonzales sealed the win five minutes from time after he took advantage of some calamitous defending to open his Clausura account.
The result sees Universitario draw level with Melgar at the summit of the table while Cienciano remain rooted to the bottom after opening with two defeats.
Apertura champions Juan Aurich crashed to their first defeat in seven games as they went down 2-1 to Cesar Vallejo.
Luis Cardoza put the visitors in front on 27 minutes before Edgar Balbuena got the home side back in it from the penalty spot on the stroke of half time.
But any momentum Juan Aurich had was lost when striker Hernan Rengifo was given his marching orders in the 65th minute for a reckless elbow on Emiliano Ciucci.
The home side held on for another 20 minutes before Andy Pando tapped home to give Cesar Vallejo their first win of the Clausura campaign.
Union Comercio saw off San Simon 3-1 thanks to a hat-trick from striker Cristian Bogado.
A sumptuous left-foot volley from the Paraguayan international opened the scoring on 24 minutes before he doubled Union Comercio’s advantage nine minutes later.
Gustavo Estanero got San Simon back in it on 37 minutes before Bogado sealed the win and his hat-trick from the penalty spot just after the restart.
An early strike from Carlos Preciado was enough to get Leon de Huanuco over the line against Universidad san Martin 1-0 while UTC Cajamarca played out a 1-1 draw with Los Caimanes.
Inti Gas also drew with Sport Huancayo 1-1, with Real Garcilaso and Alianza Lima both failing to find the back of the net as they finished their clash locked at 0-0.
