Karim Benzema, Gareth Bale and Cristiano Ronaldo all scored twice as an insatiable Madrid left the Royal Blues requiring a miracle at the Bernabeu next month despite Klaas Jan Huntelaar scoring the goal of the night in stoppage time.
"It was a perfect game. We played very well, together and helping each other," Ancelotti said on www.realmadrid.com.
"The match was fantastic. Everything went well. We played a good game because we scored two early goals and thereafter the game was more open for us. We took advantage of the counter-attack and the speed of our forwards.
"The three up top all scored and helped the side a lot."
The Italian praised the contribution of Ronaldo, on his return after suspension, and goalkeeper Iker Casillas, who made a stunning reflex save from Julian Draxler when the visitors were only 1-0 up at the Veltins-Arena.
"It was a very important moment in the game and he made an incredible and important save, because minutes later we scored the second," Ancelotti said.
"Iker was decisive. Cristiano doesn't surprise me. He was really up for the game following his ban. He prepared very well for this game and played very well."
The Madrid coach promised his side would not take the Bundesliga outfit lightly in three weeks' time despite their massive lead.
"This encounter was very good, but we have another game to play in this knockout tie," he said.
"Of course we have a large advantage but we have to play the game. We must respect Schalke, the fans and the competition. We will play as well as we can in the second leg."
Ronaldo was well up for Wednesday's first leg, having sat out three matches following his red card against Athletic Bilbao earlier this month.
"What happened has happened," said the Portugal forward, who was sent off for his reaction to a push from Carlos Gurpegi and a confrontation with Ander Iturraspe in the 75th minute of the 1-1 Primera Division draw.
"I am frustrated by it, because what I did didn't deserve a three-game ban, but I am very happy to return and score twice."
"I believe that we played a good game and the other side were not at the best because we didn't let them.
"We scored six fundamental goals and we are just one step away from the next stage and we are happy.
"In general the side were good, from Casillas and the defence to the midfield. Us forwards do our work of always trying to score goals."
On his individual display, he added: "The goalkeeper played well and made good saves. I believe in myself and my ability, and my team-mates help me a lot and they give me the confidence to play at such a high level. I scored twice in the second half so I'm very happy."