Historically, Persepolis were the club of the Tehran working classes with Esteghlal the team of Iran's elite
So important is the city derby between Esteghlal and Persepolis in Tehran, the capital of Iran, that businesses close down on the day of the game.
"Everybody, everywhere is waiting to watch the game - not just football fans," former Iran defender Mohammad Taghavi, a veteran of nine derbies who played for both teams, told BBC Sport.
"Our derby is very important to the people of Tehran and it is quite different to the derbies in England. People accept the result in the Premier League but in my country, when you lose a derby, everything changes.
"A whole season can depend on the derby. You might finish fifth or sixth, but if you win the derby, it can be more important than winning the league."
Arguably the biggest derby in Asia, the Tehran derby regularly attracts crowds of 100,000, while an average of 20 million people across Iran tune in to watch the game on television.
So big is the pressure on the players and managers that not losing has become more important than winning, and the last four derbies have ended in goalless draws.
Irish striker Eamon Zayed, left, is the only foreign player to have scored a hat-trick in the Tehran derby
In fact, the last goal to be scored in the derby was in 2012, by an Irishman.
Eamon Zayed, a Dublin-born striker who was on the books of Leicester City as a teenager, scored an 11-minute hat-trick as Persepolis fought back from 2-0 down to beat Esteghlal 3-2.
He was the first foreigner to score three goals in the derby and it made him a celebrity in Iran.
"It was all Roy of the Rovers stuff because it was only my second game for the club," said Zayed, who is a Libya international.
"The derby was front and back page news and I was asked on to their equivalent of The Late, Late Show we have in Ireland, where they count down to the new year.
"I said a few words and wished the Iranian population a happy new year."
For photos and the whole article including other 4 derbies see http://www.bbc.com/sport/0/football/29242557
So important is the city derby between Esteghlal and Persepolis in Tehran, the capital of Iran, that businesses close down on the day of the game.
"Everybody, everywhere is waiting to watch the game - not just football fans," former Iran defender Mohammad Taghavi, a veteran of nine derbies who played for both teams, told BBC Sport.
"Our derby is very important to the people of Tehran and it is quite different to the derbies in England. People accept the result in the Premier League but in my country, when you lose a derby, everything changes.
"A whole season can depend on the derby. You might finish fifth or sixth, but if you win the derby, it can be more important than winning the league."
Arguably the biggest derby in Asia, the Tehran derby regularly attracts crowds of 100,000, while an average of 20 million people across Iran tune in to watch the game on television.
So big is the pressure on the players and managers that not losing has become more important than winning, and the last four derbies have ended in goalless draws.
Irish striker Eamon Zayed, left, is the only foreign player to have scored a hat-trick in the Tehran derby
In fact, the last goal to be scored in the derby was in 2012, by an Irishman.
Eamon Zayed, a Dublin-born striker who was on the books of Leicester City as a teenager, scored an 11-minute hat-trick as Persepolis fought back from 2-0 down to beat Esteghlal 3-2.
He was the first foreigner to score three goals in the derby and it made him a celebrity in Iran.
"It was all Roy of the Rovers stuff because it was only my second game for the club," said Zayed, who is a Libya international.
"The derby was front and back page news and I was asked on to their equivalent of The Late, Late Show we have in Ireland, where they count down to the new year.
"I said a few words and wished the Iranian population a happy new year."
For photos and the whole article including other 4 derbies see http://www.bbc.com/sport/0/football/29242557