Line of Duty rose by around 300,000 viewers for Wednesday's finale, overnight data reveals.
BBC Two's drama came to an end with 2.96 million (12.9%) at 9pm. Earlier, Collectaholics brought in 1.24m (5.7%) at 8pm.
Twenty Twelve spinoff W1A launched with 1.61m (9.0%) at 10pm.
BBC One's DIY SOS topped the ratings overall outside of soaps with 4.91m (22.8%) at 8pm. Crimewatch appealed to 3.70m (16.1%) at 9pm, while A Question of Sport quizzed 1.78m (16.5%) at 10.35pm.
On ITV, You Saw Them Here First entertained 2.72m (12.6%) at 8pm (110k/0.5% on +1). Law & Order: UK dropped by around 600k from last week's opener to 3.03m (13.3%) at 9pm (328k/2.1%).
Channel 4's Secret Eaters gathered 1.06m (4.9%) at 8pm (208k/0.9%), followed by a repeat of Peter Kay's Live at the Bolton Albert Halls with 1.75m (7.6%) at 9pm (352k/2.2%). First Dates continued with 793k (4.9%) at 10pm (144k/1.7%).
On Channel 5, Born to Kill? intrigued 875k (4.1%) at 8pm, followed by the latest NCIS with 936k (4.0%) at 9pm (155k/1.0%) and Castle with 583k (3.6%) at 10pm.
ITV2's TOWIE interested 618k (3.7%) at 10pm (100k/1.2%).
Manchester United's win over Olympiakos in the Champions League scored 1.10m (5.0%) at 7.30pm on Sky1. A further 1.36m (6.4%) tuned in on Sky Sports 1.
