Mehdi Karimian netted the crucial goal after 21 minutes that means Sepahan now just need a point from their final two matches to seal the championship.
At the other end of the table, Rah Ahan boosted their survival hopes in what is shaping up to be a extremely tight relegation scrap with a 1-0 win over fellow strugglers Naft Tehran.
Iman Razaghirad's effort after seven minutes lifted the hosts out of the relegation zone and above their rivals.
Bottom side Steel Azin still have a mathematical chance of avoiding the drop after Mehdi Mahdavikia's strike 15 minutes from the end claimed three points at Malavan.
Jacques Elong's last-minute equaliser could prove crucial for Peykan as they drew 1-1 at Saipa to remain in second from bottom but just three points behind their rivals while Pas Hamedan and Shahrdari and also finished the same way.