In other major results, reigning Asian champions Pohang Steelers got their defence campaign under way with a 2-1 win over Japan's Sanfrecce Hiroshima whilst Gamba Osaka were held to a 1-1 draw by Henan Jianye.
In the west, Qatar's Al Sadd demolished the UAE's Al Ahli 5-0 as Saudi Arabian outfit Al Shabab scored a solid 3-1 away win against Pakhtakor Tashkent in Uzbekistan.
Score summaries - Asian Champions League Matchday 2
Sepahan (IRN): 0 Al Ain (UAE): 0
Pakhtakor (UZB): 1 (Alisher Azizov 78') Al Shabab (KSA): 3 (Flavio Amado 61', 74', Ahmad Alkaabi 90')
Al Ahli (UAE): 0 Al Sadd (QAT): 5 (Al Afif 36', Leandro 44', 45', 76', Yousef Ahmed Ali 64')
Al Hilal (KSA): 3 (Christian Wilhelmsson 2', Osama Hawsawi 14', Yasser Al-Qahtani 81') Mes Kerman (IRN): 1 (Ali Samereh 90')
Singapore Armed Forces (SIN): 0 Suwon Bluewings (KOR): 2(Juninho 45', Jose Mota 73')
Pohang Steelers (KOR): 2 (Jae-Won Hwang 53', Almir 90') Sanfrecce Hiroshima (JPN): 1 (Ilian Stoyanov (p) 89')