The two-hour show saw the top three finalists perform three songs each, including duets with stars such as Michael Bublé, Robbie Williams and George Michael. An average of 12.36m (48%) tuned in from 7.30pm - an identical audience figure to the previous week's performances show.
For the first time this series, the ratings were actually down on the equivalent episode from last year's run. The first half of last year's finale was watched by 13.2m (50.3%) on Saturday, December 13, 2008.
Last night the audience peaked with 14.46m (54.1%) at 9.20pm when Stacey Solomon was voted off.
ITV2's spinoff show The Xtra Factor brought in 1.16m (5.3%) in the hour from 9.30pm.
Earlier on ITV1, one-off special Cheryl Cole's Night In managed 4.94m (21.8%) from 6.30pm. It followed on from a Harry Hill's TV Burp clip show, which drew 4.33m (21.4%).
Meanwhile, the latest episode of Strictly Come Dancing put in 8.1m (33.3%) for BBC One between 6.45pm and 8pm. The results show, which aired between 9.30pm and 10pm and saw Ali Bastian leave the competition, had 7.74m (31%).
Also last night, this year's British Comedy Awards picked up 4.75m (21.8%) between 9.30pm and 11pm on ITV1.
The penultimate episode of Merlin averaged 5.22m (25.1%) for BBC One at 6pm. After Strictly, the Lottery draw took 4.29m (17.4%), then Casualty had a below-par 3.91m (15.2%). The Impressions Show With Culshaw and Stephenson followed with 3.3m (12.9%).
Channel 4's Come Dine With Me marathon averaged around 700k from 7.30pm, peaking with 910k (3.6%) for the final episode at 9pm. A screening of The Shawshank Redemption grew the audience to 1.38m (7.8%) at 9.30pm.
BBC Two's live coverage of the second semi-final of the UK Snooker Championship averaged 1.66m (6.6%) between 7pm and 10.10pm.
Five's night of US crime dramas started with NCIS, which had 717k (2.9%) at 7.10pm. CSI: NY and CSI followed with 893k (3.5%) and 959k (3.8%). Law & Order: SVU delivered 1.09m (5.2%) at 10pm, then CSI: NY closed the night with 857k (6.1%).
Overall, ITV1 averaged 36% in primetime for a comfortable first place finish. BBC One was second with 23.5%, followed by BBC Two with 6.1%, Channel 4 with 4% (+1: 0.5%) and Five with 3.7%.
BARB ratings data supplied by Attentional