Robert Lewandowski struck a hat-trick, while Kingsley Coman added a brace and Arturo Vidal, David Alaba and Arjen Robben also netted as Bayern retained a five-point lead at the top of the Bundesliga.
Muller, meanwhile, has scored just one league goal this season, but Ancelotti was quick to praise the 27-year-old after a marvellous win.
"Thomas Muller was the best player on the pitch, even if he did not score a goal," the Bayern coach said.
"Muller was the key to this victory. He moved well and was involved in every attack."
Muller meanwhile claimed he was merely delighted to contribute.
"It was really fun," he added. "At some points, [the performance] took care of itself.
"If you win 8-0, with good weather and with a good mood in the stadium, the club, the team and the fans can go home happy."
Bayern are back in action at home to Schalke in the DFB-Pokal on Wednesday.