Thiago, picked in the number 10 position ahead of Thomas Muller, hit a second-half brace as Bayern ran out comprehensive winners in the first leg of their last-16 clash at the Allianz Arena.
Ancelotti has said that Thiago's overall performance "was really good", but the fact that the 25-year-old midfielder scored twice made it "a perfect evening for him".
"Thiago played really well. We put him in a position between their lines and that position is really important for us because it allowed us more freedom in attacks and he closed down their moves well," Ancelotti told reporters. "His performance was really good and the fact he scored two goals as well made it a perfect evening for him."
Thiago has now scored five times in 25 appearances for Bayern this season, which represents the best scoring campaign of his professional career.