“The only people in the country not to guess Kate Ceberano [were] the bloody judges!” tweeted one viewer.
“Called it! Kate’s voice is so amazing and distinctive, how could you not pick it?!” said another.
Meanwhile, another viewer appeared sceptical at the judge’s apparent surprise.
“This reveal was so underwhelming, seems so contrived especially given they couldn't pick her voice when everyone on the street could.”
“Please, it was obviously the queen Kate Ceberano. How did they not guess?”
and “I think everyone guessed Kate Ceberano straight away. I did as soon as I heard the lion start singing,” read some of the other angry Tweets.
However, despite the disappointment from fans, 52-year-old Kate managed to impress with her inspiring speech following her performance.
She said: “Being in a suit you are without colour, age, size, your gender - it's completely based on what you are, you're just free.
“I have a near 16-year-old daughter. I want her to know that you can never ever be fooled by even your own insecurities, you must always give it a good, hard crack.”
On Monday, a new report made claims that The Masked Singer is rigged.
“They’re evicting people based on their celebrity status,” an insider told New Idea.
“Their plan is to get rid of the least famous people first and save the bigger names until the end so they can build up hype around the show and keep audiences intrigued.”