The Miranda Hart medical drama, which opened with just shy of 8m last week, climbed to 8.64m (30.7%) for BBC One in the 8pm hour.
Call The Midwife's audience grew healthily across the hour, with 8.2m tuning in at the start, rising to 9.1m in the final 15 minutes.
Many stuck with the channel for the premiere of Birdsong, with the two-part First World War love story adaptation commanding 6.03m (23.6%) at 9pm, while Countryfile interested 6.28m (24.4%) at 7pm.
Dancing on Ice's decline continued, with 7.1m (27.7%) for ITV1 between 6.15pm and 8.30pm (+1: 220k/0.8%), and 5.9m (23%) returning for The Skate Off at 9.30pm.
Wild at Heart, sandwiched between the reality show at 8.30pm, held up slightly better by its standards with 6.37m (23%) and 286k (1.2%) on ITV1 +1. Adrian Chiles talkshow That Sunday Night Show then mustered 2.52m (10.8%) for its latest edition.
Celebrity Big Brother ended its penultimate week with 1.77m (8.5%) in the 10pm hour, prior to which Channel 5's screening of Spiderman gripped 1.26m (4.7%) from 7pm, and World's Greatest Heroes drew 500k (1.9%) at 9.30pm.
Over on BBC Two, coverage of the Masters Final scored 1.86m (7.3%) between 8pm and 11pm.
BBC One claimed another Sunday night primetime victory over ITV1, averaging 25.3% against 22.4% (+1: 0.9%). BBC Two won the battle for third with 6.5%, ahead of Channel 4's 6.1% (+1: 0.9%), and Channel 5's 4.8%.
On the multichannels, Sky1 talent show Got To Dance grabbed 766k (3.2%) at 6pm, and 588k (2.3%) at 7pm.
BARB ratings data supplied by Attentional