Chelsea wrapped up top spot in Group G in impressive fashion, with John Terry, Willian and a Jan Kirchhoff own goal putting them in total control well before half-time.
The second period lacked the same sparkle, but substitutes Didier Drogba and Ramires completed the rout in Germany.
"They played a fantastic match," Mourinho told Sky Sports. "At this moment, this team is very mature and very confident.
"To win 5-0 away in the Champions League is not normal, playing away in Germany it is even less normal.
"The performance was very impressive. Every player individually and the team as a whole was very complete."
Mourinho insisted he will still be trying to win against Sporting Lisbon at Stamford Bridge on matchday six, but the Portuguese can afford to rest some players for that game after his side ensured they will progress as pool winners.
"We are defending well because we are defending with 11 players," added Mourinho. "We are attacking well because we are very confident in ourselves. We are a good team.
"Obviously, we can lose and maybe a bad result is waiting for us, but we are playing very well, we have big self-belief and the team is very confident.
"It's also very important for us to have one match against Sporting where we don't need the points, especially in December, which is a very busy month."
