Iran set a new record in World Cup qualifying on Thursday by keeping a 12th successive clean sheet.
Carlos Queiroz's side, who booked their place at Russia 2018 by defeating Uzbekistan last June, held South Korea to a 0-0 draw in Seoul to extend their impressive run despite being reduced to 10 men after Saeid Ezatolahi's red card in the 52nd minute.
Iran's imposing streak began with a 6-0 victory over Guam in the second round of World Cup qualifying in November 2015 and encompasses 1,108 minutes - over 18 hours - of football.
Across their entire campaign, Iran have conceded just three goals in 17 matches. Their final fixture is a home encounter with Syria on Tuesday.