Boyband Overload Generation and sisters Blonde Electra were the first acts to be eliminated from this year's X Factor live heats.
Judges Simon Cowell and Cheryl Fernandez-Versini voted to send the boys home for their "shockingly bad" performance in a sing-off with Stephanie Nala.
They were shown the door despite winning the votes of judges Mel B and Louis Walsh because they had fewer public votes than Nala.
Following last night's sing-off, Cowell said: "Neither of you had a good night last night. Boys I'm going to be honest with you that performance was shockingly bad.
"Stephanie you were good at the beginning and then went a bit off key at the end. But I absolutely cannot support an act I have no belief in at all, so I'm going to send home Overload."
Fernandez-Versini added: "I think Steph sang the best we've heard her so far."
The show featured country music and pop act Taylor Swift, who performed her current single Shake It Off, while Pharrell Williams sang Gust Of Wind.
Overload Generation said they were "gutted" to be sent home and thanked their fans for supporting them. The group were one of four wildcard acts brought back for the live shows after being kicked out initially.
Walsh, who mentored the boys, said: "I want them to stay together."
Blonde Electra were eliminated before the sing-off after securing the fewest public votes.
They said: "We've had the time of our lives. We just want to thank everybody for giving us this opportunity. This was the best time ever."