Dalton Harris, Anthony Russell and Scarlett Lee will battle it out for this year's X Factor crown following a triple elimination in the semi-finals.
Brendan Murray and Danny Tetley were the first to leave on Saturday's show. The pair were immediately eliminated having received the fewest votes from the public.
Each act performed as part of an ABBA medley in front of guest Björn Ulvaeus, while Robbie Williams rejoined the judging panel after being on tour for the previous two weeks. Nile Rodgers had stood in for Williams during his absence.
Acacia & Aaliyah then exited the competition on last night's show, losing out in a sing-off with Lee by three votes to one.
Sony Music UK artist Zara Larsson performed her latest single Ruin My Life earlier in the show.
Over on BBC One, Strictly Come Dancing welcomed legendary rocker Rod Stewart, who sang Farewell from his recent No.1 album Blood Red Roses.