Now into its ninth series, the crime series pulled in 7.42 million (30.1%), its best audience since launching on August 27.
Meanwhile, ITV1's Leaving dipped to 3.44m (14%), but added 266k (1.6%) on +1. Paul O'Grady: For the Love of Dogs managed 4.14m (16.9%) at 8pm (+1: 301k/1.2%).
Citizen Khan continued with 2.29m (16.4%) on BBC One at 10.35pm, while Panorama could only muster 2.18m (8.9%) at 8.30pm.
Channel 4's 999: What's Your Emergency maintained a solid 2.07m (8.4%) and 518k (3.1%) on timeshift, while Rude Tube amused 1.09m (6.6%) at 10pm (+1: 124k/1.5%).
Dispatches interested 2.31m (9.4%) from 8pm (+1: 491k/2%), then Food Unwrapped served up 1.83m (7.4%) at 8.30pm (+1: 279k/1.1%).
University Challenge anchored BBC Two's schedule with 2.49m (10.2%) at 8pm, before Lorraine's Fresh, Fast and Easy Food drew 2.08m (8.5%), and 982k (4%) watched 9pm's Masters of Money.
Elsewhere, Cowboy Builders was Channel 5's best-rated programme of the night with just 764k (3.1%) in the 9pm slot. Frontline Police had 720k (2.9%) an hour earlier.
Sky Sports 1's Monday Night Football match, between Everton and Newcastle, topped the multichannel lineup with 809k (3.7%) between 7pm and 11pm.
Overall, BBC One retained its primetime top spot with 22.6%, edging ITV1's 21.7% (+1: 0.9%). Channel 4 earned third place with 6.7% (+1: 1.3%), ahead of BBC Two's 6%, Sky Sports 1's 3.7%, and Channel 5's 3% (+1: 0.2%).
BBC Four's Only Connect entertained 739k (3%) in its usual 8.30pm slot.
BARB ratings data supplied by Attentional