A peak of 10.6 million viewers tuned in to watch the return of Cheryl Fernandez-Versini on the X Factor, ITV said - exactly double the peak audience of Doctor Who.
The BBC science fiction show, which overlapped with the X Factor for 15 minutes, had a peak audience of 5.3 million viewers.
This is down on the peak of 7.3 million who tuned in last weekend to see Peter Capaldi's debut as the Doctor in a feature-length opening episode of the series.
The X Factor was the most watched programme of last night by more than 4 million viewers.
The launch of the 11th series of the singing show had a 47% share of viewing, ITV said.
The peak audience tuning in on Saturday night is up on last year's launch peak by 300,000 viewers, and up on 2012's launch peak by 700,000 viewers.
The show goes international later - with mixed results - after would-be stars from around the world audition for the show.
Acts from as far afield as South Africa, Italy, Poland and Hong Kong all try to impress judges Simon Cowell, Louis Walsh, Mel B and Cheryl.
One act lost in translation is French teenager Oceane Guyot whose version of Mariah Carey's Emotions does not impress Cowell.
He tells the 19-year-old Parisian: "It was like you had swallowed a load of people and they were all screaming. It was unbelievable."
Cowell has previously defended the international appeal of his shows. After Hungarian shadow troupe Attraction won Britain's Got Talent, he said: "I like it because it makes it more of a competition, the Brits versus the rest of the world."
An act from closer to home, husband and wife Ashley Slater, 53, and Kitten Quinn, 28, from Brighton, end up confusing Walsh who tells them: "I thought it was father and daughter" only to be told by Quinn: "No, he's not my father, he's my world."