The 26-year-old Nancy hopeful found herself in the bottom two with Samantha Barks after the pair received the lowest number of votes. They were then given another chance to impress Andrew Lloyd Webber by each performing 'Memory' from Cats in the sing-off.
Struggling to decide which contestant to save, Lloyd Webber explained: "Last night Cameron and I were both saying that we thought both of you would be fantastic Nancys and now here am I faced with this. But I've got to make a decision and I've got to think of where the show ultimately for Cameron is going to go and I think I have to go with you Samantha."
Tucker admitted that she was "devastated" to be eliminated from the competition, adding: "It's been the most unbelievable experience of a lifetime and I don't regret a single minute of it."
Barks will now compete against Jessie Buckley and Jodie Prenger in next weekend's final.