The final episode of the BBC drama series drew an average of 5.08 million viewers, representing a 22.9% audience share.
Earlier in the evening, The One Show attracted 4.26 million viewers (21%) at 7pm, while Room 101 with Michael Ball and Caroline Quentin reeled in 3.16m (13.6%) at 8.30pm.
The Graham Norton Show, which featured guests such as Dallas Buyers Club actor Matthew McConaughey, was seen by an average of 3.5 million viewers (25.4%) at 10.35pm, while a transfer deadline day edition of Football Focus picked up 1.19m (13%) at 11.25pm.
Piers Morgan's Life Stories with Martin Kemp was ITV's biggest ratings success outside of soaps, pulling in an average of 3.18m (14.3%) viewers at 9pm.
Meanwhile, approximately 2.87m (13.2%) tuned in to watch The Martin Lewis Money Show, which was sandwiched between two episodes of Coronation Street at 8pm.
Mastermind was BBC Two's highest rated show, attracting 2.31 million viewers (10.5%) at 8pm, followed by 1.99m (8.6%) for The Island Parish at 8.30pm. The Natural World dropped to 1.02 million viewers (4.6%) at 9pm, before rising to 1.32m (7%) for QI at 10pm.
The Jump continues to dominate Channel 4's ratings, attracting 1.79m (8.1%) at the slightly later time of 9pm. Jamie and Jimmy's Friday Night Feast was the second highest-rated show, pulling in 1.16m (5.2%) at 8pm.
Without Celebrity Big Brother on its schedule, Channel 5's highest-rated show was Ice Road Truckers with 1.16m (5.2%) at 8pm. Ben Fogle: New Lives in the Wild was seen by 893k (4%) at 9pm.
The 11.30pm episode of Family Guy was among the highest viewed multichannel shows, drawing an average audience of 652k (7%).
Meanwhile, Blondie profile Blondie: One Way or Another was seen by 605k (2.8%) on BBC Four at 9pm.
BARB ratings data supplied by Attentional