Duran struck the only goal of the game for the 1-0 win against Southampton.
Emery said: “He was fantastic. He is progressively helping us in everything, scoring goals and sometimes not scoring but working.
“We’re very demanding with him tactically, about how to respond on the field. Today he did the work.
“The most important thing was how he worked today and then him scoring is better for the team. We’re happy for him and how we are adding another player scoring goals doing the work we need.”
Asked if Duran is now following his instructions, Emery replied: “Yes, he is (a good listener). We have to try and stop his impatient moments sometimes but that’s something natural because he’s young and he wants everything quick.
“The process we have now, he is more or less doing. Sometimes faster, sometimes slower but today the most important thing was how he worked during the 60 minutes he played.”