The key of success in this match was how RB Leipzig conditioned the build up phase of Napoli.
Basically, RB Leipzig did not allow Napoli to play in the center by the midfielders and for that was very important the positioning and actions of the 2 Forwards (Poulsen and Werner) and the 4 Midfielders (Sabitzer, Kampl, Keita and Bruma) very compact in the center and pressing the zone of the ball, especially when Koulibaly was in possession and could not play inside to the midfielders.
Conditioning the build up phase of Napoli, Leipzig could play in counter attack and create their situations to score and win the match.
Check bellow the detailed analyse and video!!