The Lord Julian Fellowes-penned Downton Abbey, which won a series of prizes at last night's 2011 Primetime Emmy Awards, delighted 8.9m (31.6%) with its return between 9pm and 10.30pm, up by 1.2m on the first series premiere last year. An additional 303k (1.8%) watched the drama on ITV1+1.
Spooks struggled against such tough competition, with the final series of the long-running spy drama entertaining just 4.62m (17%) on BBC One in the 9pm slot.
Earlier, Nature's Miracle Babies grabbed 3.11m (16.7%) on BBC One from 6pm, beating Countrywise's 2.47m (13.3%). New ITV1 quiz show Holding Out For a Hero continued with 2.64m (12.1%) in the 7pm hour, but was outperformed by Countryfile's 6.25m (25%) on BBC One from 7.30pm.
However, Antiques Roadshow's 5.53m (20.9%) on BBC One from 8pm was no match for The X Factor, which was watched by 11.19m (42.2%) on ITV1, and 286k (1.1%) on +1. Spinoff show The Xtra Factor averaged 1.11m (4.1%) for ITV2 and 155k (0.8%) on timeshift.
Channel 5's screening of 50 First Dates was enjoyed by 1.42m (7%) between 6.15pm and 8pm, before Warship sailed away with 567k (2.1%). Big Brother appealed to 1.24m (4.6%) in the 10pm hour.
A repeat of Top Gear revved up 2.03m (9.3%) on BBC Two in the 7pm hour and 125k (0.6%) on BBC HD. Documentary A South American Journey with Jonathan Dimbleby mustered 1.29m (4.9%) from 8pm, and World's Most Dangerous Roads drove away with 2.06m (7.6%) and 197k (0.7%) in HD. Match of the Day 2 scored with 3.4m (18.8%) from 10pm.
Channel 4's Grand Designs attracted 950k (4.4%) from 7pm and 173k (0.7%) on +1. New series Back From the Dead educated 820k (3.8%) in the 8pm hour and 204k (0.8%) on timeshift. A showing of He's Just Not That Into You appealed to 1.16m (5.3%) from 9pm and 268k (2.1%) on +1.
Overall, ITV1 dominated primetime with 30% (+1: 0.8%) against BBC One's 19.6%. BBC Two came in third with 9.1%, followed by Channel 4's 4.3% (+1: 0.7%) and Channel 5's 4%.
On the multi-channels, Strike Back: Project Dawn continued with 419k (1.5%) on Sky1 in the 9pm hour, while Young, Dumb and Living Off Mum took 395k (1.5%) on BBC Three.
BARB ratings data supplied by Attentional