Saturday's second episode attracted 9.67m (42.9%) to ITV1 and a further 456k to the network's HD channel between 7.30pm and 8.45pm, representing a huge 1.3m decline on last week's launch.
However, The Xtra Factor flourished with 1.83m (8.4%) for ITV2 from 8.45pm, nearly 400k up week-on-week.
Earlier on the terrestrials, 101 Ways To Leave A Gameshow and Tonight's The Night could only muster 2.44m (12.6%) and 2.31m (10.1%) at 7pm and 7.50pm respectively, as BBC One's entertainment offerings plunged.
Meanwhile on ITV1, You've Been Framed amused 3.34m (20.6%) at 6.10pm, Odd One In entertained 3.62m (20.3%) half an hour later and 3.14m (14.4%) chose Magic Numbers from 8.45pm.
Later, John Bishop's Britain put in 3.37m (15.3%) for BBC One at 9pm, then a repeat of Michael McIntyre's Comedy Roadshow took 3.82m (18.3%). The Bourne Supremacy picked up 1.95m (11.7%) for ITV1 from 9.45pm.
Ultimate Big Brother delivered 2.21m (10.3%) to Channel 4 at 9pm, while a classic edition of Have I Got News For You gave BBC Two its highest audience of the night with 2.2m (10.1%), and CSI managed 1.59m (7.4%) for Five.
Overall, ITV1 swept BBC One aside in primetime, with 23.6% (HD: 1.1%) to 15.9%. Channel 4 finished third with 8.3% (+1: 0.8%), BBC Two was next with 7.1%, and Five followed finally with 5.4%.
BARB ratings data supplied by Attentional