Ella Henderson has been predicted to claim the show's grand prize since she burst onto the show in the first auditions episode back in August.
© ITV
However, following some criticism from the judges over a couple of Henderson's live show performances and a strong couple of weeks from 21-year-old Douglas, bookmakers have switched the odds.
The supermarket worker can now be backed at 11/8, ahead of Henderson at 7/4.
James Arthur is the third favourite (3/1), ahead of Christopher Maloney (12/1) and Union J (25/1). Rylan Clark is a massive longshot to win the whole series at 80/1.
Douglas's performance of Robbie Williams's 'Angels' won him massive praise from the judges on Saturday night.
Louis Walsh described Nicole Scherzinger's act as a "star in the making", while Gary Barlow described the singer as "absolutely incredible".
Watch Jahmene Douglas covering 'Angels':
