Reza Asadi scored a stunning free-kick goal in the 70th minute in Isfahan’s Naghsh-e Jahan Stadium.
Soon after, the visiting team put Sepahan under pressure but their strikers failed to capitalize on their chances.
Persepolis forward Shahab Zahedi was shown a second yellow card in the additional time.
Earlier in the day, Zob Ahan beat Nassaji 2-1 in Ghaemshahr and moved up to second place.
Esteghlal lead the table with 22 points, followed by Zob Ahan and Persepolis, who are on 18 and 17 points, respectively.
MNA/TT