Iranian fans and footballers took protests against the country's clerical regime to the World Cup as they kicked off their campaign against England on Monday.
Pre-kick off, Iranian players did not sing the national anthem as fans booed and jeered it.
What appeared to be a sign of solidarity against their government's crackdown on demonstrators, in front of global audience of millions, is likely to embarrass the Iranian regime and could have severe repercussions for the team.
At least 419 people have been killed in the protests, including dozens of children, according to human rights groups.
The unrest began in September after the death of Mahsa Amini in the custody of the country’s morality police.
The demonstrations - or riots as Tehran refers to them - at first focused on the state-mandated hijab, or headscarf, for women, but has since become more general uprising against the Islamic Republic.
At the match on Monday, men and women held banners saying, "Women Life Freedom" and "Freedom for Iran".
Women are banned from attending men's matches in Iran.
“I’ve never attended a football match in my life so I had to take this chance,” one supporter, Mariam, 27, said.
"People at the moment they are fighting just to have their human rights," said another Iranian fan.
"We're just trying to protect our family our friends in front of the regime. Just please be our voice. Be our voice of the families and people," she said.
Many Iran fans wore T-shirts or waved banners printed with “Woman, Life, Freedom.” Others wore T-shirts bearing the names of female protesters killed by Iranian security forces in recent weeks.
In the 22nd minute of the match - a reference to her age when she died - some fans chanted Mahsa Amni's name.
Protesters had called on FIFA to ban Iran from competing in the tournament over restrictions on women in stadiums and the government's crackdown.
Iran's government had tried to encourage citizens to support their team against the country's traditional enemies. Iran will play the United States on November 29.
The team’s star forward, Sardar Azmoun, has been vocal about the protests online, while two former footballers have been arrested for backing the movement.
Hours before kick off, the English and Welsh FAs U-turned on allowing their captains to wear a 'Onelove' armband to show solidarity for in a symbol of support for LGBT+ communities for fear of players being booked.
The reprisals for the Iranian team standing silent during the country's national anthem may be far worse.