Napoli head coach Maurizio Sarri was pleased with his team's 4-1 win over FC Midtjylland at MCH Arena on Thursday, but thought they should have scored more.
Jose Callejon opened the scoring in the 19th minute and Manolo Gabbiadini hit a first-half brace, while Martin Pusic struck for the Danish side just before half-time.
The Partenopei then slowed the tempo in the second half, with Gonzalo Higuain bagging an extra goal in stoppage time, and Sarri was frustrated to see them lose their momentum.
"We did very well until going 3-0 up, then conceded their goal by being a bit complacent," the former Empoli coach told Sky Sport Italia.
"We acted as if the match was over and I didn't like the attitude in the second half, as we tried to just hold on to the result. We should've done more in the second half rather than just sit on the lead.
"I think this is a team that gives its best when it is attacking and trying to beat the opposition. We did well to sustain the pressure in a fiery atmosphere where the crowd cheered at every cross that came in."
The win in Denmark means Napoli have taken maximum points from their three group D games so far. They return to Serie A action against Chievo Verona at Stadio Marc'Antonio Bentegodi on Sunday.