The two-hour show - which saw the final four contestants perform duets with stars such as Rihanna, will.i.am and Christina Aguilera - was seen by an average of 14.05m (52.6%) from 7pm, peaking at 14.82m (56.8%) between 8pm and 8.15pm.
The Xtra Factor attracted a strong 1.17m (5.8%) to ITV2 immediately following the departure of Cher Lloyd.
Meanwhile, the new series of Take Me Out managed an impressive 6.02m (25.7%), ahead of Casualty and Armstrong & Miller which took 4.17m (15.5%) and 3.03m (12.9%) for BBC One. Prior to that, Total Wipeout fetched 3.96m (14.9%).
Strictly Come Dancing picked up 10.58m (43.1%) at 6pm, thrashing ITV1's one-off fly-on-the-wall documentary This Is JLS, which flopped with 2.58m (10.8%).
BBC Two's live snooker coverage scored 1.41m (5.6%) between 7pm and 10.15pm, then Have I Got A Bit More News For You notched up 1.99m (10.3%).
Kirstie and Phil's Perfect Christmas on Channel 4 interested 441k (1.7%) at 7pm and 537k (2%) an hour later, before Meet The Spartans appealed to 972k (4.3%) until 10.45pm.
Elsewhere, a double bill of NCIS had 751k (2.8%) and 787k (2.9%), after which CSI and CSI: NY held 1.45m (6.1%) and 1.28m (6.4%) at 9pm and 10pm.
Overall, ITV1 averaged 38.6% for a comfortable first place finish. BBC One was second with 15.7%, followed by BBC Two with 6.2%, Channel 5 with 4.4% and Channel 4 with 2.7% (+1: 0.5%).
BARB ratings data supplied by Attentional