The flying BBC One comedies pulled in near identical audiences of 6.81m (25.9%) at 9pm for Miranda Hart's sitcom and 6.79m (26.3%) half-an-hour later for Brendan O'Carroll's Irish studio comedy.
Meanwhile, the seventh and potentially final series of ITV's flagship detective drama premiered with 6.26m (24%), adding a million viewers on last year's opener.
Unlike in previous years, ITV has decided to split the stories into two hour-long parts, meaning the Kevin Whately drama will air for six weeks this year.
Elsewhere on the two main channels, Cornwall with Caroline Quentin returned with 3.9m (15.7%), while Rip-Off Britain informed 3.45m (13.7%) in BBC One's 8.30pm slot which Panorama normally fills.
What Happens in Kavos, a new factual reality format, topped Channel 4's night with 1.61m (9.3%) from 10pm (+1: 219k). Embarrassing Fat Bodies launched with 1.32m (5.1%) an hour earlier, appealing to a further 358k on +1.
Celebrity Big Brother continued with a respectable 1.91m (7.3%) on Channel 5, adding 291k an hour later on +1. The Gadget Show preceded the reality show with 781k (3.1%).
University Challenge was BBC Two's best-rated broadcast with 2.98m (12%) at 8pm, while The Polar Bear Family and Me appealed to 2.29m (10.1%) later at 9.30pm.
Overall, ITV1 led primetime with 24.7% (+1: 0.8%) over BBC One's 22.4%. BBC Two earned third place with 8.1%, ahead of Channel 4's 5.1% (+1: 0.7%), and Channel 5's 4.3% (+1: 0.4%).
BBC Four's Only Connect topped the multichannels with 928k (3.7%) in its usual 8.30pm slot, beating Stacey Dooley's BBC Three show The Truth about Magaluf which had 722k (2.8%).
BARB ratings data supplied by Attentional