The episode had 7.37 million viewers after a week of recordings - a rise of 1.67 million on the initial viewing figure of 5.7 million. That's pretty much level with The Rings of Akhaten's figure of 7.45 million.
The figure does not include those watching on iPlayer - as usual, Doctor Who was number one on iPlayer for 48 hours after the episode.
A fun fact for you - it's the eleventh episode in a row that has rated over seven million viewers - the longest run of episodes rating over seven million viewers since the 1980s.
The episode's placing in the weekly figures will be revealed tomorrow.