Doha: Qatar’s Al Duhail came from behind to shut out Iran’s Zob Ahan Esfahan FC 3-1 in their opening Group B fixture at the AFC Champions League at the Abdullah bin Khalifa Stadium here on Monday evening.     In another game, Al Gharafa, who have qualified since 2013, went down 3-2 in their away match to UAE’s Al Jazira in Group A.     The QNB Stars League leaders were stung by a 12th minute strike through Brazilian striker Kiros, who headed home from close after team-mate Morteza Tabrizi’s header ricochet off the cross bar.     The early goal had deflated Djamel Belmadi’s side, but they came back strongly with a renewed confidence in the second half to outwit their opponents thanks to a double by Qatar international Karim Boudiaf.     Boudiaf first drove home the rebound following a Youssef Msakni shot to equalise in the 74th. Two minutes later the lanky defensive midfielder headed Nam Tae-Hee corner much to the delight of his team-mates.     Attacking midfielder Youssef Msakni drilled home a Nam cross in the 84th to give Duhail a confident start in the continental club competition, which also features Al Rayyan in Group D.       Duhail next travel to the UAE to face Al Wahda in their next game on April 17.