Ansari Fard flicked home the winner after 63 minutes of a largely uninspired game, riddled with mistakes from both sides, who largely cancelled each other out in a tedious midfield war of attrition.
Iran, who have now won both their matches and are seeking a first Asian Cup title since 1976, were the better team throughout but their midfield fulcrum of Javad Nekonam and Pejman Nouri rarely found the right pass. The only goal came when Nouri crossed perfectly from the right and the unmarked Ansari Fard scored.
Iran top the group with six points, followed by the United Arab Emirates and North Korea, who both have one point. UAE were playing champions Iraq, who lost to Iran in their opening match, later.
Iran coach Afshin Ghoutbi, whose squad have been hit by a flu bug this week, was forced to make four changes from the side that beat Iraq, but thought his team had taken the lead after 28 minutes.
Ansari Fard held off a challenge from Korean defender Ri Jun-il, and fired in a well-taken shot, but the linesman flagged for handball.
Referee Nawaf Shukralla disallowed the goal then booked Ansari Fard for protesting although TV replays failed to show any infringement.
North Korea, who drew 0-0 with United Arab Emirates in their opening match, were, as expected, largely content to defend in numbers but they had two good scoring chances.
The first came after 17 minutes when striker Jong Tae-se smacked a powerful 25-metre free-kick straight at goalkeeper Mahdi Rahmati who could only parry the shot although the follow -up effort was smacked high over the bar. The second came in stoppage time at the end of the second half when Hong Yong-jo's fierce drive hit the top of the bar.
However, most of the entertainment coming from North Korea's camp was from about 200 fans, almost all of whom were identically dressed in white shirts and ties.
But even their choreographed moves and chants dried up as the match failed to produce any real entertainment apart from the goal.
New darling
Ismaeel Abdulatif is the new darling of Bahrain after he claimed four goals -- including a 19-minute first-half hat-trick -- in his team’s 5-2 win over India on Friday.
The 24-year-old Al Hala foward netted from close range in the 16th and 19th minutes after Faouzi Aaish’s opener had been cancelled out by Gouramangi Singh and completed his hat-trick with a slick finish 10 minutes before half-time.
India pulled another goal back through Sunil Chhetri before Aaish was dismissed after being shown a second yellow card for diving. But Abdulatif slammed home a fine individual goal late on at the Al Sadd stadium to put the game beyond India and send himself to the top of the tournament scoring charts. “It was his time to score,” said Bahrain team-mate Jaycee John, who set up Abdulatif’s second goal. “He had a lot of chances and if I find that I’m in a position to set something up and he’s in a better position than me to score, then I will give him the ball because we want to get the goals and the three points for the team.”