The Andrew Lincoln-starring zombie drama's second season, which has already aired on digital channel FX, logged 906k (5.6%) between 10pm and 11.30pm - nearly 40% down on the equivalent first season opener last April.
Elsewhere, Landmark documentary series Seven Up! returned with a respectable audience last night (Monday), overnight data reveals.
Michael Apted's first edition of 56 Up, revisiting the lives of Sue, Paul, Neil and Peter after another seven years, logged 4.49m (19.1%) in the 9pm hour and 310k on ITV1 +1.
Factual programmes aired on all five terrestrial channels in the 9pm slot, with BBC One's aristocratic series Chatsworth opening with 4.13m (17.6%) to take second place.
Meanwhile, The 70s mustered 1.43m (6.1%) for BBC Two, just ahead of Secret Millionaire's 1.34m (5.7%) for Channel 4 (+1: 213k), and Robson's Extreme Fishing Challenge's 1.13m (4.8%) for Channel 5.
BBC Two's 1970s-themed night concluded with 1.43m (7.3%) for Sound of the 70s, while 1.04m (6%) watched Ramsay's Kitchen Nightmares USA on Channel 4 (+1: 135k).
Panorama interested 2.48m (10.8%) for BBC One at 8.30pm, while The Dales mustered 3.69m (16.2%) at 8pm (+1: 105k).
Overall, ITV1 led primetime fairly comfortably with 22.9% (+1: 0.8%) against BBC One's 19.3%. BBC Two claimed third place with 6.2%, beating Channel 4's 4.8% (+1: 0.6%), and Channel 5's 3.9% (+1: 0.2%).
Dark BBC Three one-off human interest film - The 16-Year-Old Killer: Cyntoia's Story - topped the multichannel lineup with 879k (3.8%).
BARB ratings data supplied by Attentional