On the results show, Olly accidentally told Monica Michael that she would be going home before reading out the results from the public vote.
The judges announced the names of who they wanted to save between Monica and Anton Stephans after their sing-off, and being the last one to vote, Simon Cowell took the decision to deadlock.
But Olly read out the result before he and Caroline Flack had been handed the envelope containing the result.
Looking confused, Caroline was quick to interrupt, telling viewers that the decision had indeed gone to deadlock, so they would read the results from the public vote.
Olly was full of apologies, saying sorry to the audience, the judges and Monica profusely. Caroline then proceeded to announce the results of the public vote.
I apologise to everyone tonight I made a massive f%#k up at the end. It was so tense!! I'm still learning & hope that never happens again!— Olly Murs (@ollyofficial) November 15, 2015
It turns out Monica was in fact the contestant with the fewest votes, and so she was eliminated from the competition.
Taking to Twitter after the show, Olly tweeted: "I apologise to everyone tonight I made a massive f%#k up at the end. It was so tense!! I'm still learning & hope that never happens again!"
Co-host Caroline said: "We all make mistakes. I make LOADS in life and on telly ... It's live."
Monica was eliminated from the competition with Max Stone, who received the fewest votes of the night.
As a result of the slip up, Olly's name was trending on Twitter with more than 50,000 tweets about the gaffe.
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