The five-piece boyband were eliminated from the competition after finishing bottom of the series's first public vote with Frankie Cocozza.
In a final sing-off for judges, Nu Vibe performed 'Promise This' by Cheryl Cole, while Cocozza selected Daniel Merriweather's 'Red' as his survival song.
When host Dermot O'Leary came to the panel for their decision, Cocozza's mentor Gary Barlow first stated that he didn't believe his act deserved to be in the final two, saying: "Hopefully it's going to be a long time before you're singing a survivial song [again]."
Following Barlow's vote to eliminate Nu Vibe, Kelly Rowland struggled to make her own choice, saying that she found it "so hard" to pick between the two. She eventually opted to send home Nu Vibe.
Tulisa Contostavlos followed Barlow's example by choosing to save her own act and eliminate Cocozza, leaving Louis Walsh with the deciding vote.
"It's tough, neither act had a really good night," he said of their performances yesterday. "I'm going to save the act that i think has the most potential in the competition."
Walsh went on to name Nu Vibe as his choice for eviction, ending the group's X Factor dream.
Asked by O'Leary what she thought went wrong for Nu Vibe, Contostavlos replied: "I'm not sure, all I can say is I believed in them. I took a chance and they worked hard, they gave everything. I still believe in them now and I wish they could stay in this competition."
The N-Dubz star gave her backing to the boys' decision to stay together, telling them: "Just keep going. All of them are such beautiful lads. They're talented and they deserve it."
The X Factor continues next Saturday at 8pm on ITV1.