Tonight's dramatic ninth episode featured the Girls and the Overs fighting for their futures on the ITV talent contest.
While Robbie Williams and Louis Tomlinson took it easy for the night, Simon and Ayda struggled to decide exactly who they should be taking to Judges' Houses.
As usual, successful contestants sit in one of six chairs representing places in the next round - but the line-ups aren't final until the last person sings.
If someone better comes along later, the judges can free up space for them by sending an already seated act home.
However, some lucky hopefuls will avoid that uncertainty this year, thanks to a new twist dubbed the 'Golden X'.
Similarly to Britain's Got Talent's Golden Buzzer, each judge can press the Golden X button once to guarantee a 'safe seat' to their favourite act - meaning they can't be swapped out again.
Here's a rundown of all the latest results…
Simon Cowell & The Girls
Kleo (Seat) - A regular performer at African festivals, Kleo entered The X Factor to represent her continent - and did that quite literally by performing Shakira's World Cup anthem 'Waka Waka (This Time For Africa)'. "You're a great performer, I love that you bring something different to this competition," said Ayda. "You have great personality, that's what I really like about you," commented Simon, who promptly gave her the first of his six empty chairs.
Georgia Burgess (Seat) - Georgia thought the experience of her first audition was "incredible", and that emotion was reflected in her Six Chair song choice - 'Happy' by Pharrell Williams. "I think that was a brilliant take on that song," said Louis, before Simon gave the temp worker a chair.
April Darby (Seat) - April, a singer from Amsterdam, instantly won over Robbie by performing his signature track 'Angels'. "Seat, seat, seat," he smirked. "I thought that was a great version of the song, so go and take seat number three please," smiled Simon.
Ava Lily (Seat) - 24-year-old singer-songwriter Ava also drew inspiration from the judging panel for her song choice, opting for the One Direction track Perfect - and becoming the fourth out of four acts to be given a chair. "Oh my God, there's so many of us and two chairs," mused one worried hopeful waiting backstage.
Maria Laroco (Seat) - Although admitting she was "really nervous", 17-year-old Maria insisted to Simon that she was ready for the competition - and backed her statement up with a bold cover of Whitney Houston's 'Queen of the Night'. "You've got a huge personality, a huge voice, you're incredible," reviewed Robbie. For Simon, it was a no-brainer to give her the fifth chair.
Sephy Francisco (Seat) - Sephy got a standing ovation at her audition her after surprising double voice shocked the crowd - and she pulled the same trick out the bag for Six Chair by singing Loren Allred's 'Never Enough' in two vastly different tones. "This is gonna stand out, this is gonna be remembered, go and take a seat," instructed Simon - filling up his last empty spot in the process.
Bella Penfold (Golden X, replaced Kleo) - With all of Simon's spots occupied, Bella was the first contender who had to fight to dethrone another act. She went all out to convince Simon, telling him: "If these chairs represent hard work, dedication, the willing to learn and potential, then I think I deserve a seat." She thrilled the crowd with her cover of Stormzy's 'Blinded By Your Grace Pt 2', and the judges were equally as impressed. "I think you're phenomenal, I really do. Great vocals, great rapping," commented Robbie. "My pet hate is every Tom, Dick and Harry thinking they can rap, but you should be rapping. I think you're the full package," added Louis.
Simon immediately riled the crowd when he announced he wouldn't be giving her a seat - but the reason for that became clear when he went and pressed the Golden X button, guaranteeing Bella a spot at Judges' Houses. He decided that her 'safe seat' would be number one, making Kleo the first act to be sent home.
Lanya Matthews (Seat, replaced April) - Lanya argued that she brings something "different" and "old-school" - and her huge voice on Whitney Houston's 'I Didn't Know My Own Strength' convinced Simon to keep her in the competition at April's expense. "The fact that you've just pulled out that vocal at 17 is unbelievable," commented Louis.
Jennifer Owens (Seat, replaced Maria) - Jennifer was the first act to take the risk of debuting original material at the Six Chair Challenge, a track entitled 'Fly'. It appeared to be the wrong move when Simon interrupted her and asked her to sing acapella, much to the disdain of the other judges. "If Spongebob Squarehead doesn't put you through, I would like to cover your song," joked Robbie. Her fears proved unfounded when Simon decided to give her Maria's chair…
Maria Laroco (Seat, replaced Ava) - …however, that decision that proved very unpopular with the crowd. Bowing to calls of "bring her back", Simon invited Maria to return, taking Ava's place.
Shan (Seat, replaced Georgia) - Songwriter and session singer Shan is hoping to have her moment on The X Factor, having grown up watching the show. She pulled a crowd-pleasing performance of Sia's 'Alive' out of the bag, and it dawned on Simon that the process was getting tougher. "If Simon doesn't give you a seat, I'll take mine and put it on that stage for you," pledged Ayda. The Syco mogul eventually decided to grant her Georgia's place.
Georgia Burgess (Seat, replaced Lanya) - As if the Six Chair Challenge wasn't already dramatic enough, Georgia then gave Simon an even bigger dilemma. Not willing to give up easily, she asked to sing another song, whipping up the crowd for support. Simon caved, and she belted out Robin S's floor-filling dance track 'Show Me Love'. "Way to get your hustle on!" exclaimed Ayda. "You came out fighting," added Louis. Admitting he "admires her determination", Simon decided to hang on to Georgia, bidding farewell to Lanya as a result.
Molly Scott (Replaced Sephy in Seat 6) - Molly in particular found the Six Chair Challenge scary, as at just 16 years of age, she felt she may not have as much experience as her rivals. However, she easily held her own with a piano rendition of A Great Big World's 'Say Something'. "It's not just about your voice, it's about how far you're willing to fight," observed Ayda. Clearly Simon felt Molly has enough fight in her, as he granted her Sephy's place.
Scarlett Lee - Scarlett has a bad history with the Six Chair Challenge. During her original series last year, she was the first person to win a seat - only to become the last person to be sent packing. Eager to avoid the same fate this time around, she took to the stage to face Simon - who hasn't exactly been her biggest fan, and quickly reminded her how she previously "screwed up". He was left eating his words after her performance of Kelly Clarkson's 'Piece By Piece', which Louis described as "absolutely incredible".
Simon informed Scarlett that she'd be taking a seat, but he couldn't decide which one. The episode ended on a cliffhanger as he announced that there would be a sing-off to determine the final result - but we won't find out who's involved until tomorrow.
Ayda Field & The Overs
Olatunji Yearwood (Seat 1) - First up from the Overs was Olatunji, who hails from the Caribbean and wants to get the world listening to Soca music. While he performed an original song for his "electric" audition, for Six Chair he opted for the Lou Bega classic 'Mambo No. 5'. "I think this competition needs people like you, you bring personality," proclaimed Simon, as Ayda gave Ola her first seat.
Anthony Monarch (Seat 2) - Anthony wanted to have a bit of a party and get the crowd up on their feet, and he did just that by performing Walk The Moon hit 'Shut Up And Dance', earning Ayda's second spot.
Cezar Ouatu (Seat 3) - Cezar has wowed the judges with his operatic voice, and got to show off his pipes again on the West Side Story classic 'Somewhere'. "You stepped up, you grabbed everybody's attention, I think it was absolutely amazing," said Louis. Ayda wasted no time in telling him to "go grab your seat".
Jacqueline Faye (Seat 4) - Jacqueline's been having the time of her life on The X Factor, as she told the judges before her rendition of the Les Misérables track 'Bring Him Home'. "You're all that's great about Great Britain," cooed Robbie. The 53-year-old was sent to chair four, which later proved to be somewhat cursed.
Burgandy Williams (Seat 5) - Burgandy came all the way from America for a chair, and she successfully won one with a diva-tastic performance of Whitney Houston's 'I'm Every Woman' - thanks in part to Simon chanting "seat, seat, seat".
Claire Angel (Seat 6) - Claire surprised the judges with an image transformation, ditching her vibrant purple hair for a long white do. She felt she didn't "deserve" a chair, saying she "believes in earning something" - and earn it she did, ending her cover of 'Bridge Over Troubled Water' with a powerful long note.
Ricky John (Golden X, replaced Anthony) - Having followed Simon's lead by filling all six openings with her first six acts, Ayda called Ricky to the stage. The 36-year-old - who spent years living on the streets - was hungry for success, claiming he's "not really gonna get many more shots like this in life". Aiming to do his newborn proud, he performed Otis Redding's 'Try A Little Tenderness' to roaring applause from the Wembley audience. "It's time for you to drop the self doubt, trust me," said Robbie. "You absolutely killed that. We believe in you, you've got to believe in you."
With Ricky's birthday occurring just two days after filming, Ayda announced she was going on stage to give him a birthday hug - then gave him a surprise early present by swerving over to hit the Golden X button. The jubilant carpenter leapt off stage and lifted Ayda in to the air - but it was a bittersweet moment for Anthony, who lost his place to give Ricky his safe seat.
Antonino Spaddacino (Seat, replaced Jacqueline) - Antonino says music is the "first love" of his life, and he'd give everything to keep making it forever. The Italian demonstrated his husky vocals on Rihanna's 'Stay', and Ayda liked his tone enough to give him Jacqueline's spot in seat 4 - but he didn't get to keep it for long.
Ivo Dimchev (Seat, replaced Antonino) - Bulgarian choreographer Ivo tried to impress Ayda by offering to write a "beautiful love song" for her hubby Robbie to sing to her. Like at his audition, he performed an original song - but also like his audition, he divided the audience, with some jeering and giving him the thumbs down. "There's something fantastically bonkers about you, this is one I'm gonna remember," said Simon. Ayda compared Ivo to Marmite - but she likes Marmite, and again cleared seat 4 so he could hang around.
Panda Ross (Seat, replaced Ivo) - There was yet another seat 4 swap-out when Panda took to the stage. The American barista has history with Simon as a three-time contestant on The X Factor USA. It turns out Ayda also loves a slice of Panda pie, giving her a chair - even though she was unconvinced by her performance of Jennifer Hudson's 'You Pulled Me Through', noting: "Your song choice today was not good, but I also see so much potential in you."
Louise Setara (Seat, replaced Panda) - Not even Panda could keep hold of seat 4, as Ayda emptied it a fourth time for Louise. The Camberly cleaner felt "all kinds of emotions", having never thought she'd have the courage to attempt The X Factor - but you wouldn't have been able to tell from her confident take on Ella Henderson's 'Beautifully Unfurnished'. "Your two little lads will be very proud of you today," assured Louis, while Simon remarked that it would be "criminal" for her to be sent home.
The X Factor continues tomorrow at 8.00pm on ITV.