Stefano Pioli praised his Milan team for showing the same will to win at Celtic that saw them to victory over Inter in the derby.
A 3-1 win over the Scottish champions in the Europa League on Thursday was a fine way for Milan to launch their Group H campaign.
Coming just five days after a 2-1 triumph over Inter, it was all the more pleasing to the head coach.
Goals from Rade Krunic, Brahim Diaz and substitute Jens Hauge saw off Neil Lennon's side at Parkhead.
Pioli said: "We handled the game well, even if in the second half we were less technically precise and we risked a little bit.
"It was important to show that we are not a normal team that shows less of a stimulus after such a desired victory as the derby.
"The secret? We all work in one direction, club, technical staff, players, we all feel involved."
Speaking to Italian broadcaster Sky Sport, Pioli added: "The secret lies in work, sacrifice and the desire to improve."
Milan return to Serie A action on Monday when they face Roma.
Pioli's team have won four from four to top the table and they are unbeaten in 21 games now across all competitions.
"Our strength is to think that the next match is always the most important, and we have to go forward with this mentality," Pioli told Milan TV.
"In harmony we work much better. I always tell the players to take advantage of every moment and improve more and more, because in football tests never end: you always have to prove.
"On Monday we will have a very important and difficult test, against a strong opponent with quality, especially at an attacking level. We will do our best to continue this positive streak."