David Walliams and Catherine Tate's new series amused 4.24 million (20.6%) at 9pm. A repeat of Mrs Brown's Boys attracted 3.61m (17.8%) at 9.30pm.
Earlier, Celebrity MasterChef appealed to 3.25m (15.8%) at 8pm, dipping around 200k from its previous episode.
On BBC Two, Mastermind quizzed 1.65m (8.6%) at 8pm, while new series Burrowers: Animals Underground interested 2.17m (10.6%) at 9pm.
ITV's Food, Facts & Fiction brought in 3.03m (16.2%) at 8pm (129k/0.6% on +1). A Doc Martin rerun gathered 2.93m (14.3%) at 9pm.
On Channel 4, 8 Out of 10 Cats Does Countdown entertained 1.26m (6.2%) at 9pm (392k/2.4%).
Channel 5's live Big Brother eviction of Sophie Lawrence was seen by 1.60m (8.2%) at 9pm (111k/0.8%). Bit on the Side followed with 833k (6.6%) at 10.30pm.
BARB ratings data supplied by Attentional