An average of 8.79m (41.9%) - up from 2013's figure of 7.7m - saw Austria's Conchita Wurst beat the Netherlands' The Common Linnets to be crowned champion.
On ITV, Britain's Got Talent continued with 8.68m (41.1%) from 7pm, with an additional 710k (3.2%) on +1. Britain's Got More Talent on ITV2 managed 1.34m (6.1%) afterwards.
Meanwhile, ITV's Amazing Greys attracted 2.05m (9.3%) in the 8pm hour.
Over on BBC Two, Flog It! and Dad's Army managed 1.02m (4.8%) and 1.45m (6.7%) respectively.
They were followed by A Culture Show Special from 8.30pm (352k/1.6%) and Generation War: Our Mothers, Our Fathers at 9.30pm (810k/3.9%).
Channel 4 showed The Day the Earth Stood Still from 7.05pm (720k/3.3%) and Man on a Ledge from 9pm (1.31m/6.1%).
Meanwhile, Channel 5 aired The Battle of Britain, which averaged 847k (3.8%).
On the multichannels, ITV3's Doc Martin was watched by 800k (3.6%) from 8pm, while a showing of Pirates of the Caribbean: The Curse of the Black Pearl entertained 944k (4.3%) on BBC Three.