Amir Ebrahimzadeh starred with five goals as Iran, who was made to work hard for its opening day 1-0 win over Kyrgyz Republic, strolled to victory against Brunei Darussalam at the Dolen Omurzakov Stadium.
Midfielder Mohammad Reza Torabi put them ahead in the 23rd minute and that paved the way for total domination as Ebrahimzadeh (27th) and Mojtaba Fakhrian (45+1) secured a comfortable lead going into the break.
Iran was relentless in the second half with Hossein Hajizadeh scoring its fourth in the 56th minute.
It was the Ebrahimzadeh show after that as he struck in the 67th, 70th, 71st and 77th minutes to complete an impressive win for Iran.
Iran will play the UAE in Group J on Sunday.