An average of 34.8% tuned in as Tom Jones and will.i.am welcomed new mentors Kylie Minogue and Ricky Wilson.
The sing competition dampened ITV's Splash!, which went head-to-head in the 7pm to 8:30pm slot. 3.45m (14.4%) watched as Anna Williamson and Keith Duffy made it through to the semi-finals. A further 275.6k (1.1%) caught the action an hour later on ITV+1.
Casualty's latest episode also performed well from 9:15pm to 10:15pm, attracting 5.15m (22.1%). Earlier in the evening Dynamo performed well for BBC One, with 3.73m (20.7%) watching Magician Impossible at 5:45pm.
ITV's most-watch programme for the night was Take Me Out, which wooed 4.14m (17.5%) from 8:30pm to 9:45pm (+1: 305.8k, 1.4%). The channel also chilled 2m (10.8%) at 5:15pm with a showing of Ice Age 2: The Meltdown (+1: 168.7k, 0.8%).
BBC Two led its schedule with a repeat of Nature's Weirdest Events. The episode attracted 1.99m (8.4%) as Chris Packham continued his exploration of the nature's most bizarre and extraordinary happenings.
Later on in the evening, 1.98m also tuned into a repeat of Morecambe and Wise in Pieces, giving the channel another 8.4% share of the audience.
Meanwhile, Channel 4's debut episode of Hostages entertained 1.17m from 9pm to 10pm. 5% of the audience were gripped as a surgeon is ordered to assassinate the President during surgery in order to save her family who are being held hostage. A further 215.7k (1.0%) also caught the opening episode an hour later on +1.
Over on Channel 5, 1.89m (8.7%) watched the latest instalment of Celebrity Big Brother at 9:45pm, as Dappy and Luisa Zissman were involved in an explosive argument (+1: 177.4k, 1.2%). 780.5k (5.6%) stayed with the channel at 10:45pm for Celebrity Big Brother's Big on the Psych.
Sky Sports 1 led the multichannels, attracting 2.26m (6.6%) from 5pm with Saturday Football Night Live, while BBC Three pulled in 1.1m (4.8%) viewers with a showing of Pirates of the Caribbean: On Stranger Tides at 8:30pm.
BBC Four's thriller The Bridge continued its second season with a double-bill, pulling in 946.3k (4.0%) at 9pm and 825.1k (4.0%) for its second episode of the night at 10pm.
ITV2 attracted 973.5k (4.3%) at 8:30pm with the eighteenth movie in the James Bond franchise Tomorrow Never Dies.
BARB ratings data supplied by Attentional
Catch up on all the latest TV and Movies releases in Digital Spy's Screen Time: