Featuring Blue and Jedward as the UK and Ireland entries, the event - eventually won by Azerbaijan - pulled in a colossal 9.54m (40.4%) between 8pm and 12am, peaking with 12.7m (62%) at 11pm.
This is in stark contrast to last year's lowest ever UK audience of 5.5m.
BBC One's strong evening sent ITV1's audience sinking, as Piers Morgan's Life Stories plummeted to a dismal 2.19m (8.8%) at 9pm.
Britain's Got Talent, meanwhile, fell to a still-respectable 8.1m (32%) at 8pm with a further 260k on +1, then Britain's Got More Talent had 912k (3.7%) and 102k on timeshift.
Doctor Who's universally praised Neil Gaiman episode 'The Doctor's Wife' - guest starring Suranne Jones and Michael Sheen - logged 6.09m (29.5%) for BBC One at 6.40pm, after which Doctor Who Confidential mustered 679k (3.2%), BBC Three's best audience of the day.
Sing If You Can held its lead over So You Think You Can Dance with a steady 4.17m (20%) for ITV1 in the 7pm hour. The BBC One dance show entertained just 2.71m (16.2%) at the much earlier time of 5.30pm, and 3.06m (14.2%) returned for the results at 7.10pm.
Over on BBC Two, Domesday and Have I Got A Bit More News For You nabbed 928k (3.7%) and 1.32m (5.3%), while The Untold Battle of Britain and The Million Pound Drop fetched 835k (3.3%) and 1.4m (5.7%) for Channel 4.
Elsewhere, NCIS, CSI: NY and CSI: Miami notched up respective audiences of 997k (4%), 1.63m (6.5%) and 1.03m (4.5%).
Overall, BBC One crushed ITV1 in primetime with 33.6% to 16.8% (0.5%). BBC Two claimed third place with 6%, followed by Channel 5 with 4.7%, and Channel 4 with 4.3% (+1: 0.4%).
The FA Cup Final scored a healthy 4.3m (34.9%) between 1pm and 5.30pm for Manchester City's win over Stoke, peaking with 8m (52.6%) at 4.30pm.
BARB ratings data supplied by Attentional