The romantic comedy, featuring Men Behaving Badly star Neil Morrissey, could only muster 2.42m (an 11.2% share) in its 9.30pm junction.
BBC Two documentary Natural World overtook BBC One between 9.30pm and 10pm as a result, averaging 2.62m (11.8%) in its full one-hour slot.
Have I Got News For You managed nearly double the audience of Me and Mrs Jones from 9pm until 9.30pm, as Damian Lewis's night in the hot seat drew 4.72m (20.6%).
Meanwhile, a celebrity edition of Who Wants to be a Millionaire? interested 3.26m (14.7%) on ITV1, as well as 179k on +1.
Channel 4's third part of Derren Brown's controversial Apocalypse attracted 1.46m (6.6%) and 257k on timeshift, while Alan Carr: Chatty Man entertained 1.38m (7.9%) from 10pm (+1: 257k).
Elsewhere, QI commanded a decent 2.69m (13.7%) for BBC Two at 10pm, while 3.8m (26.3%) watched The Graham Norton Show on BBC One from 10.35pm.
The Mentalist anchored Channel 5's schedule with an audience of 1.43m (6.4%) in the 9pm hour, adding a further 142k on +1.
Overall, ITV1 topped primetime with 21.1% (+1: 0.7%), beating BBC One's 18.2%. BBC Two earned third place with 9.5%, comfortably ahead of Channel 4's 5% (+1: 1%), and Channel 5's 3.7% (+1: 0.2%).
BARB ratings data supplied by Attentional