According to overnight data, an average audience of 7.89 million (35.2%) tuned in to watch this weekend's show, which saw performances from Adele's cousin Georgia, and Vicky Jones - the sister of McFly's Danny Jones.
Over on ITV, Tom Daley's Splash! attracted 3.54m (16.25) at 6.45pm, as Richard Whitehead and Austin Healey made it through to the semi-finals of the diving competition.
Back on BBC One, 5.03m (23.6%) played along with National Lottery: Who Dares Wins at 8.15pm, while 4.65m (21.6%) tuned in to watch Casualty at 9.10pm.
A repeat of the first ever episode of Mrs Brown's Boys amused 4.72m (23.5%) at 10pm.
BBC Two's biggest primetime ratings came from an episode of Dad's Army, which pulled in 2.02m (9.19%) at 8pm. Morecambe & Wise in Pieces: At Home entertained 1.79m (8.34%) at 8.30pm, while 1.39m (6.61%) tuned in to QI XL at 9.30pm.
Back on ITV, Take Me Out was viewed by 3.73m (17.39%) at 8.15pm, while The Jonathan Ross Show attracted 2.26m (10.93%) at 9.30pm.
Approximately 211k (1.4%) watched the presenter chat to guests including Sam Bailey, Robert Lindsay and Rufus Hound an hour later on ITV+1.
US drama Hostages was Channel 4's highest-rated show, pulling in 750,000 viewers (3.49%) at 9pm. Earlier in the evening, Speed with Guy Martin brought in 540k (2.44%) at 7pm, while Bigfoot Files fascinated 570k (2.63%) at 8pm.
Celebrity Big Brother continued on Channel 5, with 1.75m (8.42%) tuning in to see housemates take part in the selfies task at 9.30pm. A triple-bill of NCIS did well for the channel earlier in the evening, with 878k (4.69%) watching the night's third episode at 8.30pm.
ITV3's Midsomer Murders topped the multichannel ratings. Roughly 1.05m (5.28%) watched the detective drama at 9pm.
A double-bill of The Bridge attracted 973k (4.52%) and 831k (4.49%) viewers to BBC Four at 9pm and 10pm respectively.
BARB ratings data supplied by Attentional