The four-piece girl group closed the first live show of the series by singing Mary Mary's 'Shackles (Praise You)'.
They put their own spin on it by inserting a rap about their time on the ITV talent contest.
Lyrics included: "We at the semi-finals of BGT, if we make it to the final, be like OMG."
However, there was one line in particular that caught Simon's attention.
"Holla, holla, Miss Treats are so real, holla, holla, Simon, give us a deal," they continued.
He may not be drawing up a contract yet, but the media mogul was impressed with their performance.
"You know what, I think you may be one of the most underrated acts of the show so far," Simon reacted.
"For me in the real world this is probably the best act I've seen on the show tonight.
"What I like about you is you've got personality, you're focused. I think there's a gap in the market for you."
David Walliams echoed his comments, saying: "If I were Simon, I'd be making you sign that record deal tonight."
Former Mis-Teeq member Alesha Dixon added: "I think it's so much harder for girl groups, you have to fight harder than anyone else.
"I thought the harmonies were great. There is so much potential."
Miss Treat Vibe will have to wait until the results show at 9.30pm to find out whether they'll return for the final.
This year their fate is entirely in the hands of the public, as bosses have taken power away from the judges.
Viewers' votes alone will decide which two of tonight's eight contestants will go through to the series finale on Sunday.