Esteghlal is two points behind leader Persepolis.
Winfried Schaefer’s side defeated Naft Masjed Soleyman thanks to Ali Karimi’s ninth minute goal at the Azadi Stadium in Tehran.
Earlier on the day, Persepolis was held to a 1-1 draw by Nassaji in nothern city of Ghaemshahr.
Mehdi Nazari scored for the host in the 23rd minute and Soroush Rafiei equalized the match in the 62nd minute.
In Isfahan, Sepahan beat Pars Jonoubi 1-0. Kiros Stanley scored the winner in the 45th minute.
On Thursday, Tractor Sazi defeated Machine Sazi 2-0 in Tabriz Derby. Ashkan Dejagah and Anthony Stokes were on target for Tractor Sazi.
Saipa edged past Foolad in Tehran, struggling Esteghlal Khuzestan lost to Paykan 1-0 in Ahvaz and Zob Ahan beat Padideh 1-0 in Mashhad.
Persepolis remains top of the table with 42 points.
Sepahan is second with 41 points and one game in hand.
Esteghlal and Tractor Sazi are third and fourth respectively with 40 points.