Set in and around the corridors of power, Bodyguard tells the fictional story of David Budd (Richard Madden), a heroic but volatile war veteran now working as a Specialist Protection Officer for the Royalty and Specialist Protection Branch (RaSP), assigned to protect the ambitious and powerful Home Secretary Julia Montague (Keeley Hawes).
The new series launched last month to 6.7 million viewers - a number which rose to 7 million viewers and then 8 million last weekend.
A 75-minute extended finale on Sunday was seen by an average audience of 10.4 million between 9PM and 10:15PM.
It was BBC One's most-watched drama since 2008 and the biggest on any UK TV channel since Downton Abbey in 2011. It's also the biggest non-World Cup viewing figure of 2018.
The episode hit a peak audience of just over 11 million as viewers found out the truth about the characters.
Over on ITV in the 9PM slot, Vanity Fair unsurprisingly fell against the competition.
ITV's adaptation of William Makepeace Thackeray's novel began with 3 million viewers but was down to 2.1 million yesterday.
Earlier, episode eight of The X Factor achieved just over 5 million viewers, a rise on last Sunday and matching Saturday's showing. The latest series continues below a million viewers on 2017.
Sunday was the final day of auditions with acts including we met Thomas Pound, 20 year old cleaner from South Wales also known by his drag alter ego Lady Frieda Wilde.
Joining him through to the next round were Chloe Jane McAllister, an 18 year old from Northern Ireland, 16-year-old student Blaise Duncan, 18-year-old student Jon Guelas and 18 year old Elliot Horne.
Finally, there was ATTY, a family group of four who brought a bit of gospel to the arena.
The X Factor will be back next Saturday and Sunday with the Six Chair Challenge after bootcamp was dropped.