Life of Crime debuted with 3.9m (17.7%) viewers at 9pm on Friday (May 10), overnight data shows.
ITV's three-part drama follows the career of police officer Denise Woods, played by Hayley Atwell, over three decades in the Met.
In the same timeslot on BBC One, Have I Got News for You earned 4.58m (20.2%) and Not Going Out had 3.86m (17.6%).
Earlier, A Question of Sport attracted 3.15m (15%) at 7.30pm and Would I Lie To You grabbed 2.88m (12.2%) an hour later. The Graham Norton Show was watched by 3.65m (25%) at 10.45pm.
On BBC Two, Pride and Prejudice: Having a Ball interested 1.5m (7%) at 9pm, prior to which Nature's Microwave and Gardeners' World grabbed 1.72m (7.8%) and 2.14m (9.1%) respectively.
The Martin Lewis Money Show brought 3.1m (14.1%) to ITV at 8pm and The Suspicions of Mr Wicher attracted 1m (8%) from 10.30pm.
Meanwhile, Channel 4's Ben Earl: Trick Artist had 800k (3.6%) at 9pm and Alan Carr's Chatty Man was watched by 1.22m (6.9%) at 10pm.
The Mentalist was seen by 938k (4.2%) on Channel 5 at 9pm, while Eddie Stobart: Trucks and Trailers had 983k (4.3%) at 8pm.
Family Guy was the highest rated broadcast across the digital channels, earning 747k (7.1%) for BBC Three at 11.20pm.
