The X Factor final last night was down four million viewers on the previous year, figures showed today.
The ITV1 programme had an average audience of 13.1 million, compared to the 17.2 million who watched as Matt Cardle triumphed in the 2010 competition.
And it was the lowest average audience for the finale of the series since 2007, when Leon Jackson won the show.
Last night's peak audience for The X Factor - which has been down on the previous year throughout much of the series - was also four million fewer, drawing 15.5 million at its height.
ITV drew comfort from the series being the third most successful in The X Factor's eight-year history. The final helped to boost the series average up to 11 million viewers across the 17-week run.
ITV pointed out that BBC One rival Strictly Come Dancing had averaged 9.7 million viewers this series.
Meanwhile, girls came out on top every week during the latest X Factor series, new figures show.
Voting patterns from throughout the series have been released by programme bosses which show the boys did not get a look-in from the start. And the eventual winners Little Mix did not head the list until the seventh week of the 10 live heats.
Irish teenager Janet Devlin led the viewers' voting for four straight weeks and only lost her position when Amelia Lily was voted back into the competition. From then on it was Amelia or Little Mix who went on to lead each week. And girl group Little Mix were then clear favourites from the semi-final onwards.