The BBC Three lesbian drama's 239k (1.2%) in the 9pm hour is a third of the audience it attracted for its first series aired late on Tuesday nights in 2010.
However, BBC Three was still the joint most-watched multichannel station, thanks to Russell Howard's Good News Extra (611k/4.2%) at 10.30pm.
Piers Morgan's Life Stories ended another run with 3.93m (19.1%) in the 9pm hour with 235k on +1, staying behind BBC One's Have I Got News For You (4.41m/21.1%) but overpowering a repeat of Michael McIntyre's Comedy Roadshow (3.08m/15.2%).
Elsewhere on BBC One, Would I Lie To You? amused 2.73m (13.5%) at 8.30pm, while 3.29m (23%) watched Graham Norton at 10.35pm. Poms in Paradise grabbed 2.74m (14.7%) for ITV1 at 8pm (+1: 156k).
Over on BBC Two, Episodes rallied over 100k week-on-week to 1.1m (6%) at 10pm, prior to which the launch of factual series The Great British Story: A People's History interested 1.53m (7.4%). Chelsea Flower show coverage was seen by 1.96m (10%) in the 8pm hour.
Comedian Alan Carr anchored Channel 4's schedule with Chatty Man, which entertained 1.48m (7.5%) at 10pm and 200k on timeshift. Meanwhile, 8 Out of 10 Cats drew 956k (4.5%) at 9pm (+1: 302k) and Very Important People continued with 744k (3.7%) at 9.30pm (+1: 103k).
The Mentalist pulled in 1.24m (6.2%) to Channel 5 at 9pm, then 847k (4.9%) stuck with the Richard Desmond network for Castle.
Overall, ITV1 won primetime with 22.9% (+1: 0.8%), ahead of BBC One's 20%. BBC Two grabbed third place with 7.1%, followed by Channel 4's 4.8% (+1: 0.9%), and Channel 5's 4.2% (+1: 0.2%).
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BARB ratings data supplied by Attentional