Wednesday's quarter-final first-leg clash marked another high point in the Ballon d'Or-winner's incredible campaign, as he equalled Lionel Messi's record of 14 Champions League goals in a season during the 3-0 win over last season's European runners-up.
The Portugal captain was booed by his own supporters during Saturday's 5-0 thrashing of Rayo Vallecano at the Bernebeu, but his name was being chanted around the famous stadium after he scored Real's third goal against Dortmund to take his remarkable tally for the season to 45.
Ancelotti revealed last week that Ronaldo was carrying a minor knee injury and the Italian brought the former Manchester United man off with 10 minutes remaining against the side who beat the Spanish giants in the semi-final last term.
But he played down concerns that his prolific forward could face a spell on the sidelines at such a crucial stage of the season, as his side attempt to win the treble of Champions League, La Liga and Copa del Rey.
"Cristiano had a knee injury," Ancelotti said.
"I've taken him out to avoid risks. He is not injured, just a minor annoyance."
Ancelotti's vow to attack the German side paid dividends as Gareth Bale put Real in front after just two minutes, then Isco doubled their lead before half-time.
Dortmund struggled to cope with the home side's attacking threat, but they caused problems at the other end and Ancelotti praised the contribution of his defence and the manner in which they kept Jurgen Klopp's side at bay.
He added: "I'm satisfied with the score and the attitude of the team. It wasn't an easy game but we started well. Then we slowed down and Dortmund are a very dangerous team on the break.
"Now we have to play in Dortmund. They use dangerous and quick counter-attacks, but our defence was good. We also pushed up to avoid their long passes."
