The return of Broadchurch has given ITV its biggest drama audience since Downton Abbey in 2015.

The first episode of the final series of the crime drama drew 7.5 million viewers, giving the channel a 34% audience share and winning the 9pm timeslot.

The cast of Broadchurch
Broadchurch has been a massive hit for ITV (ITV)

Meet The Lords on BBC Two drew 1.7 million, while BBC One’s Crimewatch attracted 1.5 million.

The final episode of Downton Abbey on Christmas Day in 2015 drew 6.6 million viewers in the overnight ratings, as people tuned in to wish a fond farewell to the Crawley family.

The penultimate episode of the period drama in November of that year pulled in 8.8 million.

Downton Abbey
Downton Abbey (Nick Briggs/ITV/PA)

Broadchurch returned on Monday for a third and final series as Olivia Colman and David Tennant as DS Ellie Miller and DI Alec Hardy lead an investigation into a rape in the fictional Dorset town.

The series premiere fell slightly short of the first episode of series two, which launched in 2105 to 7.6 million, while the first episode of the first series pulled in 6.8 million.

Police and rape counsellors have praised the makers of the drama and said they hope the storyline will encourage victims to come forward.

Olivia Colman and David Tennant in Broadchurch
The handling of the new storyline has won praise (ITV)

Viewers were moved by harrowing scenes in which Trish Winterman, played by former Coronation Street actress Julie Hesmondhalgh, recounted being raped in the series opener.

The show’s writer, Chris Chibnall, said he wanted to tell the story after continued increases in the number of sexual offences being reported to police.