The medical drama, starring James Nesbitt as neuroscientist Gabriel Monroe, averaged 4.86m (20%) for ITV1 in the 9pm hour, down 1.04m on last week's debut episode. An extra 173k (1%) tuned in on ITV1 +1.
Monroe was also outperformed by The Big Red Nose Day Desert Trek, featuring celebrities such as Dermot O'Leary and Olly Murs attempting to cross Kenya's Kaisut Desert, which delivered 4.94m (20.5%) on BBC One.
Earlier, Tonight: Man Vs Mother Nature fetched 3.18m (14%) on ITV1 from 7.30pm and DIY SOS: The Big Build - Chessington built 3.59m (14.8%) on BBC One in the 8pm hour. Question Time brought in 2.67m (22.1%) on BBC One from 10.45pm.
Channel 4's Coach Trip mustered 1.65m (10.5%) from 5.30pm and 312k (1.6%) on +1. Later, Relocation, Relocation located 1.55m (6.4%) in the 8pm hour and 231k (1%) on timeshift. Love Thy Neighbour took 820k (3.4%) from 9pm and 107k (0.6%) on +1. 10'Clock Live was seen by 700k (4%).
Over at BBC Two, Decade Of Discovery enchanted 1.36m (6.1%) in the 7pm hour, before A Farmer's Life For Me served up 1.26m (5.2%) from 8pm. The British At Work mustered 1.33m (5.5%) in the 9pm hour and ICC Cricket World Cup Highlights had 1.44m (6.6%) from 10pm.
Live coverage of Liverpool's goalless UEFA Europa League draw with Braga pulled in 2.91m (12.3%) on Channel 5 between 7.30pm and 10.15pm.
Overall, ITV1 narrowly won primetime with 21.8% (+1: 0.5%) against BBC One's 21.4%. Channel 5 came in third with 9.6%, ahead of BBC Two with 5.6% and Channel 4 with 4.4% (+1: 0.7%).
Elsewhere, Celebrity Juice amused 1.13m (5.9%) on ITV2 from 10pm, the biggest multichannel audience of the night. A further 195k (1.9%) watched the show on timeshift. Skins entertained 381k (2.2%) on E4 from 10pm and 136k (1.4%) on +1.
BARB ratings data supplied by Attentional