Reus said that the most important thing was to create plenty of chances, and although Pepe Reina made a number of saves the German international thought the attackers performed well.
"I think we were a lot more aggressive tonight than we were against Bayern at the weekend," UEFA.com quotes Reus as saying. "We forced a lot more chances which was important for us. We started well and gained confidence through the early goal and once we hit our stride I thought we deserved to win 3-1.
"It would have been nice to have scored our second or third goals earlier to calm things down, but to be honest I am just happy we are creating the chances in the first place. We did not let our heads drop, we kept getting forward and remained dangerous."
Dortmund are above Napoli because of a better head-to-head record against them.