An average audience of 4.5 million tuned in to watch the live final of the fifth series of The Voice, according to overnight figures, down from 6.3 million in 2015, 6.6 million in 2014 and a high of 7.2 million in 2013.
The show hit a peak of 6.1 million in its slot only after the opening episode of BGT had finished on ITV, and just in time to see former Liberty X singer Kevin Simm crowned the 2016 winner against singers Jolan, Cody Frost and Lydia Lucy.
ITV triumphed with the first episode of the 10th series of Britain's Got Talent, which was Saturday night's most watched show, drawing in nine million viewers and a market share of 41%.
However, the number was markedly less than last year's first round of auditions, which premiered at an average of 10.5 million viewers.
Audiences were enthralled as the series opened with an eye-wincing sword-swallowing act, and they saw 13-year-old Beau Dermott sent straight through to the live rounds after judge Amanda Holden used her Golden Buzzer.
With a peak of 10.4 million viewers, the BGT launch was ITV's highest rating programme of the year so far.
The network will be hoping to improve the ratings of The Voice when the singing competition finds a new home on its flagship channel in 2017 after the BBC decided not to enter into a bidding war for another series.
Judges Paloma Faith - who mentored Simm - Boy George, Ricky Wilson and Will.i.am are yet to confirm their involvement in the next series.