The channel has suffered on Tuesdays for many months, often finishing last place for the night amongst the terrestrial broadcasters - behind even Five - and averaging around a million viewers.
Autumnwatch, a two-week natural documentation of life on Brownsea Island, Dorset, brought in 3.26m (14.2%) in the 8pm hour. The audience is significantly up on the 1.35m (5.8%) who saw Twiggy's Frock Exchange in the same slot last week and almost beat ITV1's Who Wants To Be A Millionaire?, which had 3.57m (15.5%) at the same time.
BBC One's Holby City won the slot with 5.12m (22.2%) and on Channel 4, fashion show Miss Naked Beauty - which this week was accused of "humiliating" its contestants - drew 1.92m (8.4%). Five had 1.12m (4.9%) for Nature Shock documentary 'The Whale That Blew Up In The Street'.
At 9pm, Spooks drew 5.06m (22.2%) to BBC One, a fall of 450,000 on Monday's debut. ITV1 was second for the hour, enticing 3.37m (14.8%) to Cops With Cameras, while Channel 4's Embarrassing Teenage Bodies interested 2.59m (11.4%).
Five had 1.96m (8.6%) for CSI: Miami, leaving BBC Two in last place with Twiggy's Frock Exchange. The audience was up 370,000 week-on-week though, averaging 1.35m (5.9%) for the hour.
Neil Morrissey's Risky Business, a new Channel 4 series following the comedian's attempts to open his own pub, began with 1.2m (7.1%) at 10pm (+1: 120,000, 1.5%). It was out-rated by a repeat of CSI: New York on Five, which had 1.57m (9.1%).
BBC One had an average share of 22.8% in primetime (last week: 23%), ahead of ITV1's 17.6% (21.7%). BBC Two was up to a respectable 8.1% (5.4%), Channel 4 had 7.8% (8.3%) and Five had 6.1% (7.9%).
EastEnders led the multichannel ratings, with 959,000 (5.6%) tuning in for BBC Three's 10pm repeat.
The second episode of original horror drama Dead Set managed 822,000 (4.9%) for E4 at 10pm (+1: 218,000, 2.4%), down a third on Monday's impressive debut. First-run Hollyoaks was also a hit for the channel, with 705,000 (4%) at 7pm (+1: 100,000, 0.5%).
On ITV2, Haunted Homes picked up 415,000 (2.1%) in the 8pm hour (+1: 72,000, 0.4%) then a screening of Bond movie Tomorrow Never Dies had an almighty 823,000 (5.1%) until 11.25pm (+1: 231,000, 2.2%).
Ratings data supplied by Attentional