Mehdi Mehdipour gave the Iranians a lead two minutes after the interval. A hat trick from Amir Abbas Aeinechi in the 57, 83 and 89 minutes sealed a 4-0 victory over Lebanon for Iran. Iran is to play Bahrain on Tuesday.
Iran had been held to a goalless draw by Tajikistan in its opener. The defending champion defeated Nepal 3-0 in its second match.
The AFC U-16 Championship is a football competition organized by the Asian Football Confederation (AFC) held once every two years for Asian under-16 teams.
A total of 23 teams have been divided in four groups. The top four teams qualify for the FIFA U-17 World Cup.