Doha // Iran became the first team to qualify for the quarter-finals of the Asian Cup after Karim Ansari Fard's second-half goal secured victory over North Korea.
Ansari Fard converted Pejman Nouri's cross in the 63rd minute to settle what was a largely poor Group D encounter at Qatar Sports Club Stadium as Iran followed up their opening 2-1 triumph over neighbours Iraq with another victory.
Iran coach Afshin Ghotbi hailed his players, and said: "It's a fantastic achievement to qualify for the quarter-finals in our group. I am very proud of our players."
There was little in the way of goalmouth action in a dour opening 45 minutes.
Jong Tae-se stung Iran goalkeeper Mahdi Rahmati's hands with a free-kick after 16 minutes, and Ansari Fard had a goal ruled out for handball at the other end before Jong again tested Rahmati.
The opening exchanges in the second half also failed to produce any meaningful chances. Mohammad Reza Khalatbari's weak shot that was easily dealt with at his near post by Ri Myong-guk was the only real action before Iran took the lead just after the hour mark.
A throw-in on the left released Nouri and the midfielder whipped in a low cross towards Ansari Fard. The striker guided the ball with the outside of his boot past the diving Ri and into the far corner to finally break the deadlock.
North Korea showed more attacking desire after falling behind as they tried to break down Iran.
Hong Yong-jo nearly snatched an injury-time equaliser when he managed to lose his marker to collect a low cross, turn and shoot from 12 yards but the ball grazed the top of the crossbar, much to his and his country's disappointment.