Shahriar Moghanlou, Mohammad Daneshgar, Mojtaba Moghtadaei (own goal) and Omid Nourafkan were on target for the host.
In Ahvaz, Foolad was held to a 1-1 draw by Zob Ahan. Havadar drew 1-1 with Nassaji and Mes Rafsanjan played out a goalless draw against Malavan.
The match between Aluminum and Gol Gohar, slated for Sunday, was postponed due to heavy snowfall in Arak.
Sepahan sits second with 24 points, one point behind IPL leader Persepolis.
Sunday’s Fixture:
* Persepolis v Paykan
* Sanat Naft v Esteghlal
* Tractor v Mes Kerman
* Aluminum v Gol Gohar (postponed)