Despite being down 200k week-on-week, the drama averaged a steady 5.74m (24.4%), again annihilating Comedy Rocks With Jason Manford, which had 2.91m (12.3%).
Earlier on, Children's Hospital delivered 3.16m (12.7%) at 8pm, while QI grabbed 3.9m (15.7%) for BBC One at 8.30pm.
Over on BBC Two, Mastermind and Life In A Cottage Garden took 2.5m (10.1%) and 1.61m (6.5%) in the 8pm hour, then Can't Take It With You attracted 1.62m (6.9%), and Fast And Loose amused 1.35m (6.7%) at 10pm.
Elsewhere, Channel 4's combination of Relocation: Phil Down Under and The 50 Funniest Moments 2010 mustered 1.58m (6.4%) and 1.63m (7.9%), while Ice Road Truckers, CSI and NCIS logged 1.51m (6.1%), 1.47m (6.3%) and 1.16m (6.2%) for Channel 5.
BBC One's overall primetime share was 22.4%, ahead of ITV1's 21.1%, BBC Two's 7.4%, Channel 4's 6% (+1: 0.7%) and Channel 5's 5%.
BARB ratings data supplied by Attentional