Doha: Qatar's Al Duhail completed the 2018 AFC Champions League group stage with an impressive 100 percent record, after Abdelrahman Fahmi's goal gave them a 1-0 win over Al Wahda of the UAE on Matchday Six.   Having already secured their berth in the pre-quarters, Al Duhail coach Djamel Belmadi rested some of the key players and opted for a number of youngsters in yesterday’s match.   The hosts were handed an advantage in the 39th minute when Al Wahda defender Salem Sultan was sent off after pulling down Youssef El Arabi who was through on goal.   At the Abdullah Bin Khalifa Stadium in Doha, Fahmi made the most out of the opportunity he was given and scored the winner for the home team in the 47th minute.   The match saw little action at either half thereafter, and only came alive in the 84th minute, when Al Duhail were also reduced to 10 men after Lucas Mendes was shown his marching orders.   The decision had no effect on the result and Al Duhail held on to clinch their sixth straight victory and become just the fourth side in history to win all their group games in the AFC Champions League.   Belmadi's men will now play Group D runners-up Al Ain in the Round of 16.