The song and dance collective will join Singer Station in the Five reality show final after impressing with their rendition of 'Total Eclipse Of The Heart'.
Meanwhile, 87-strong Sing Live, who are comprised of 11 choirs, were handed the wildcard by the judges after they finished in the sing-off with BLOK. Sing Live will now get a second chance to win a slot in the final when they take part in a wildcard show in four weeks' time.
Praising Three Spires, judge Anastacia said: "I cared for it. I cared for all of it. I thought that your singing was amazing."
Chucky Klapow added: "That was rockstar ready. I would pay to see that. It was entertaining."
Duncan James said that the collective were superior to other acts because they had managed to "come together as a show choir", while Tamzin Outhwaite praised the troupe's "complete theatrics".
Don't Stop Believing continues next Sunday at 8pm on Five.