Drogba missed Chelsea's opening three Group D games due to suspension following following his foul-mouthed confrontation with Norwegian referee Tom Henning Ovrebo after last season's semi-final against Barcelona.
He returned with a bang on Tuesday night, netting both of his side's goals in a 2-2 draw with Atletico Madrid. Drogba might even have been celebrating a hat-trick but his powerful free-kick just after half-time had been turned onto the post by the diving Sergio Asenjo.
After the game, Ancelotti heaped praise on Drogba and although he stopped short of saying the 31-year-old was the best striker in the world, he admitted he would not trade the former Marseille man for anyone else.
"I don't know (if he is the best). For sure, I want to keep him. I don't want to change him with any other striker," said Ancelotti.
"Didier is an important player for us. We have a lot of important players but he is doing very well and we are happy. I'm very happy with his behaviour, and I hope he continues like this."