The Senegalese scored a hat-trick in the 3-1 win over fellow Iranian side Zob Ahan on Tuesday in Tehran’s Azadi Stadium.
The Tehran side conceded in added time in last week’s first leg as a 1-0 defeat in Isfahan left them with plenty to do at Azadi Stadium, where more than 75,000 fans generated a fantastic atmosphere at the Islamic Republic of Iran’s national stadium.
“This is a very good win because we know that we are better than our opponent, so we are very happy to achieve this victory,” said Thiam.
“We know we are a good team and now we have to give our maximum to get to the final,” he added.
Thiam’s treble means the striker is now on seven goals for the campaign, after joining Esteghlal in February. He is just two behind the tournament’s joint top scorers Baghdad Bounedjah of Al Sadd and Youssef El Arabi of Al Duhail, with both sides also still in the competition.