Jamaica Inn dropped almost 2 million viewers for its second episode on Tuesday (April 22), according to overnight figures.
BBC One's Cornish drama - which was hit with sound issues on Monday night - fell to 4.4m (18.9%) at 9pm. A repeat of BBC Three's Life and Death Row interested 1.4m (14.6%) at 10.35pm.
On BBC Two, The Big Allotment Challenge dipped over 500k to 1.9m (8.1%) at 8pm. Earlier, Great British Menu gathered 1.8m (8.3%) at 7.30pm, while Watermen: A Dirty Business appealed to 1.7m (7.5%) at 9pm.
ITV's coverage of Chelsea's Champions League draw with Athletico Madrid scored 4.1m (18.3%) at 7.30pm.
On Channel 4, Embarrassing Bodies intrigued 1.2m (5.2%) at 8pm (225k/1.0% on +1). New Worlds' finale episode dipped to a new low of 312k (1.4%) at 9pm.
Channel 5's Nightmare Neighbour Next Door fascinated 1.2m (5.2%) at 8pm (103k/0.4%), followed by The Mentalist with 935k (4.0%) at 9pm (241k/1.5%) and Law & Order: SVU with 779k (4.7%) at 10pm (127k/1.4%).
On BBC Three, The Call Centre entertained 1.1m (4.6%) at 9pm, while Sweat the Small Stuff was seen by 468k (2.6%) at 10pm.
MTV's new series Ex on the Beach achieved its highest average audience amongst 16-34-year-olds for the launch episode of a new series, attracting 328k (2.0%) overall at 10pm.