Outcasts, about a group of pioneers attempting to build a new life on another planet, averaged 2.95m (11.8%) for BBC One from 9pm, down 1.5m on last Monday's debut episode.
The drama was outperformed by The Biggest Loser in the 9pm hour, after the weight-loss reality show pulled in 4.03m (16.1%) on ITV1 and 157k (0.9%) on ITV1+1.
Earlier, The One Show grabbed 4.89m (22%) on BBC One from 7pm, before Inside Out took 3.43m (14.3%). The Lakes entertained 3.85m (15.3%) on ITV1 from 8pm and 61k (0.2%) on +1.
Panorama: Wikileaks - The Secret Story mustered 2.16m (8.4%) on BBC One from 8.30pm and A Question Of Sport fetched 2.46m (16.7%) from 10.30pm.
Channel 4's Coach Trip returned with a solid 1.82m (11%) from 5.30pm and 278k (1.3%) on timeshift. The reality programme soundly beat Channel 5's new magazine show OK! TV, which entertained a rather modest 449k (2.1%).
Later on Channel 4, Dispatches: Lessons in Hate and Violence fetched 1.13m (4.4%) from 8pm and 204k (0.8%) on +1. It was followed by One Born Every Minute, which had 2.78m (11.1%) and 374k (2%) on timeshift. Alan Carr: Chatty Man talked to 1.23m (7%) from 10pm and 199k (2.2%) on +1.
Channel 5's How Do They Do It? mustered 755k (3.1%) from 7.30pm, before The Gadget Show returned with 1.13m (4.4%) in the 8pm hour. Royal Navy Caribbean Patrol sailed in with 1.96m (7.9%) in the 9pm hour, before Steven Seagal Vs Justin Lee Collins captivated 974k (5.4%). A screening of Half Past Dead was watched by 974k (5.4%) from 11.15pm.
Over on BBC Two, Geert Wilders: Europe's Most Dangerous Man? took 790k (3.4%) from 7pm. University Challenge and Baking Made Easy mustered 2.66m (10.5%) and 2.17m (8.4%) respectively in the 8pm hour. Horizon: How to Mend A Broken Heart educated 1.33m (5.3%) in the 9pm hour, before Episodes amused 1.12m (5.5%). Later, series four of Mad Men had 270k (3.6%) from 11.30pm.
Overall, ITV1 won primetime with 25.3% against BBC One's 17.6%. Channel 4 came third with 6.4% (+1: 0.9%), followed by BBC Two with 5.9% and Channel 5 with 4.9%.
Glee averaged 1.36m (5.4%) for digital channel E4 from 9pm, the biggest multichannel audience of the night. A further 283k (1.6%) watched the musical comedy on E4+1.
BARB ratings data supplied by Attentional