Al Ain: Qatar's Al Duhail continued their impressive run in the 2018 AFC Champions League with an impressive 4-2 away win over UAE's Al Ain in the first leg of their Round of 16 clash at the Hazza bin Zayed Stadium on Tuesday.   The visitors started the game the more energetic side and stunned the home fans when Moroccan striker Youssef El Arabi struck in the 16th minute.   Al Ain goalkeeper Khaled Eisa did well to save El Arabi's initial header but the Al Duhail frontman pounced on the rebound and hit a powerful effort that went in off Mohamed Ahmed.   Nam Tae-hee then doubled the lead for the Qataris in the 39th minute with a magnificent solo effort. The Korea Republic star nutmegged Ahmed Barman near the halfway line before sprinting away from Mohammed Abdulrahman and netting past Eisa to make it 2-0.   Al Duhail picked up from where they left off in the second half and Ismail Mohammad put his side further ahead in the 48th minute with a fine chip over Eisa, after being set up by Nam.   Nam was involved in Al Duhail's fourth goal just seven minutes later, threading a through ball for Almoez Ali, whose fierce low strike went in at the near post to give the Qatari side a scarcely believable 4-0 lead.   Al Ain's fightback only gathered steam towards the last half hour, with two substitutes helping them reduce the deficit.   Ahmed Khalil was first, heading in from close range in the 68th minute to make it 4-1. In the 86th minute, Ibrahim Diaky popped up in the six-yard area to slam home a rebound after Amine Lecomte parried Omar Abdulrahman's free-kick.