Derren Litten's series five conclusion, which featured Doctor Who legend Kate O'Mara, attracted 5.57m (24.4%) for ITV1 at 9pm and 349k (1.9%) on timeshift.
The Steve Pemberton sitcom's last episode is up on the 2011 finale, but overall this series is 440k down on last year.
A Lionel Ritchie special at 10pm, replacing News at Ten, fetched 2.52m (13.8%) and 151k (1.4%) on timeshift.
BBC One had an extremely disappointing night, logging only 2.44m (10.2%) for Len Goodman's Titanic documentary at 8.30pm, and 2.7m (11.8%) for Land of the Lost Wolves at 10pm.
Over on BBC Two, Hugh Bonneville's Twenty Twelve held all of last week's audience, amusing 972k (4.9%) at 10pm.
Mastermind (1.82m/7.9%) and Gardeners' World (1.93m/8.1%) were consistent in the 8pm hour, after which factual series Brick By Brick: Rebuilding Our Past drew 1.38m (6.1%) from 9pm.
Davina McCall's Million Pound Drop anchored Channel 4's schedule with 1.51m (6.8%) between 9pm and 10.30pm (+1: 172k/1%), either side of which Come Dine with Me (8pm) climbed to 1.04m (4.4%) and 257k (1.1%) an hour later, while Rude Tube slipped to 762k (5%) from 10.30pm (+1: 151k/0.8%).
Elsewhere, Eddie Stobart: Trucks and Trailers took 1.25m (5.3%) for Channel 5 at 8pm, then 1.48m (6.5%) tuned in for The Mentalist.
Overall, ITV breezed to victory in primetime with 23.7% (+1: 0.6%), far ahead of BBC One's 15.2%, BBC Two's 6.4%, Channel 4's 4.9%, and Channel 5's 4.7%.
BBC Four's Queen night earned the digital channel 1.06m (5.7%) in the 10pm hour for concert Days of Our Lives.
BARB ratings data supplied by Attentional