Tractor’s Reza Asadi converted his penalty in the 64th minute.
Sepahan put the host under pressure but its strikers lacked cutting edge.
Elsewhere, Esteghlal edged past Aluminum 1-0 in Arak, courtesy of a goal from Mehdi Ghaedi in the 55th minute.
Paykan defeated Havadar 1-0 in Tehran and Zob Ahan earned a 1-0 win over Gol Gohar in Isfahan.
Sepahan and Esteghlal football teams are level on 52 points at the top of the Iran Professional League (IPL) table, while Persepolis sits third with 51 points.