Doctor Who Series 7, Episode 3: A Town Called Mercy had an overnight audience of 6.6 million viewers, with a 29.1% share of the total TV audience.
Doctor Who was overall third for the day, being beaten by the return of Strictly Come Dancing, which achieved 8.0 million viewers, and The X Factor, which managed 9.0 million.
ITV1's Red or Black?, which was on at the same time as Doctor Who, managed 3.6 million viewers, while Dad's Army on BBC Two had a figure of 1.9 million.
With Sunday's ratings still to come, this figure places Doctor Who in 14th place for the week.
Overnight figures are an estimate of those who watched the programme live, or before 2am the following day.
Final viewing figures figures, which will be available early next week, will include those who watch the programme within a week.