Sophie was unmasked and while Dannii Minogue guessed correctly, Jackie apparently didn't know her good friend was the one singing the whole time and instead guessed drag queen Courtney Act.
However, there was some deception on Sophie's end with the singer explaining she had taken a call from Jackie while backstage, as the radio host was attempting to check her friend's alibi, ultimately throwing her off the scent.
Sophie explained how she had taken Jackie's call backstage, saying, "I'm so sorry! Do you know how hard that was for me? Keeping that lie for so long?"
"I feel like such an idiot!" Jackie exclaimed.
Sophie responded, "I know, I feel so bad."
Jackie had called Sophie a week earlier while on the show, with Sophie rubbishing the claims she was the Dragonfly.
Jackie told her, "So everyone thinks you're the Dragonfly, well some people, Hughesy's convinced."
Sophie said, "Oh god, do you know how many people have asked me if I'm that moth? So I hope I'm getting paid by Channel 10 for this s**t!"
After being unmasked on the show, Sophie said, "I have to thank The Masked Singer Australia. I was embarrassed to sing in the shower. I have not sung for 17 years, I got burnt by the industry. Jackie always asked if I would sing again and I said never.
"There’s something about the disguise that makes it so much easier to just bring out confidence. You’re not worrying about what people think about you, no one was judging me, I could just sing."
While on the Kyle and Jackie O Show on Tuesday morning, Kyle and a producer made fun of Jackie for not guessing Sophie correctly.
"I was yelling at you on the TV, Jackie!" the producer said.
"Stop it though, oh don't!" the embarrassed host said, adding, "There were definite times, guys, that I was going, 'No, this is Sophie Monk', but... I know, I know."
Production shut down
Meanwhile, production of The Masked Singer was shut down after seven crew members tested positive for coronavirus.
The plug was pulled on Saturday just two hours out from filming the grand finale.
Speaking to The Project on Sunday night via video link, Osher revealed how close the production came to filming the finale of the entertainment show.
"We were literally two hours away from hitting record on our grand finale," Osher said.
"The pyrotechnics were loaded, everyone was in costume and we were ready to go.”
He went on to say a young person put their hand up and said "hold on guys, I’m not feeling well", and after that "they were brave enough to pull the emergency brake on the freight train and then we hit stop and everyone shut down".
Osher went on to say that he, along with other cast and crew from Sydney, were supposed to fly back to Sydney on Sunday, instead they went and got a test for the coronavirus in Melbourne.
There are three more weeks worth of episodes already filmed, however the grand finale is still up in the air.
The finale will be filmed when they get the all clear.