The Christmas special, featuring previously lost footage of David Bowie performing 'The Jean Genie', pulled in an average of 2.56m (11.2%) between 7.30pm and 9pm.
Between 8.30pm and 9pm, BBC Two overtook BBC One as TOTP2 peaked with 2.94m (12.7%) compared to The Impressions Show's 2.68m (11.5%).
A Downton Abbey behind-the-scenes special, teasing Sunday's Christmas special, drew 4.26m (18.8%) for ITV1 at 7.30pm (+1: 241k/1%), then 4.35m (18%) watched A Night of Heroes: The Sun Military Awards from 8.30pm (+1: 157k/0.7%).
BBC One's Royle Family repeat mustered 3.88m (15.7%) in the 9pm hour, while Obsessive Compulsive Hoarder - a Cutting Edge series - opened with a decent 2.67m (10.8%) for Channel 4 (+1: 608k/3.1%), and Rick Stein's Spanish Christmas logged 1.4m (5.7%) for BBC Two.
Following Stein at 10pm, Ruth Jones' Christmas Cracker (1.48m/7.2%) got the better of Vernon Kay's Home for Christmas, which slumped to 685k (3.6%) on Channel 4 (+1: 122k/1%).
Elsewhere, Channel 5's Cowboy Builders took 871k (3.8%), losing out to Kirstie's Home for Christmas, which grabbed 1.29m (5.6%) and 190k (0.8%) on Channel 4 +1.
Movie Bad Santa settled a mediocre evening for Channel 5, averaging 1.02m (4.6%) between 9pm and 11pm.
Overall, ITV1 led primetime with 18.3% (+1: 0.7%), beating BBC One which had 17%. BBC Two was comfortably in third place with 8.4%, ahead of Channel 4's 5.9% (+1: 1.3%) and Channel 5's 4.2%.
BARB ratings data supplied by Attentional