The series, which first aired in 1997 and stars John Nettles as DCI Tom Barnaby, attracted a 29.7% share of the audience at 8pm-10pm.
BBC One's 'Miss Austen Regrets', in which Olivia Williams played Jane Austen in a drama set in the writer's later years, could only draw 3.9m viewers and a 15.4% share between 8pm-9.30pm.
Dramatisations of Austen's novels normally guarantee big audiences so a drama based on the writer's letters and a primetime slot on Sunday evening would have been expected to pull in a sizeable audience.
The BBC's disappointment will only be matched by ITV's glee at trouncing the corporation with a decade old drama, which has already seen DCI Barnaby investigate more than 132 suspicious murders.
Channel 4's terrestrial premiere of the acclaimed movie 'In Her Shoes', which stars Cameron Diaz and Toni Collette in a sentimental family drama, pulled in 2.3m viewers and a 12.3% share at 9pm. Including Channel 4+1's time shifted audience, the film was watched by 2.4m and 12.9%.
Earlier in the evening, Channel 4's adventure series 'Bear Grylls: Born Survivor' was watched by 1.4m viewers and a 5.3% share between 8pm-9pm. Including Channel 4+1, the third episode of the six-part series drew 1.6m and 6.1%.
ITV1's 'F1: Spanish Grand Prix Live', in which British driver Lewis Hamilton took third place on the podium in Barcelona, scored 3.4m viewers and a 29.6% share between 12pm-3.05pm.
The broadcaster's fourth episode of satirical comedy 'Headcases' netted 2.8m viewers and a 14% share at 10pm, well below the 4m it had for the opening episode.
On Saturday evening, ITV1's primetime smash hit 'Britain's Got Talent' managed 9.4m viewers and a 41.2% share at 8.05pm-9.05pm, compared to an average audience of 10.3m for last week's instalment.
The US import 'Pushing Daisies' sunk to 3.8m viewers and a 17.5% share, down from 4.7m last week, at 9.05pm-10.05pm.