Amanda Holden, 48, shared a snap to her Instagram of herself posing in the jaw-dropping frock just minutes before the start of the episode.
The star’s outfit certainly didn’t disappoint, as it boasted an extremely low-cut neckline.
Amanda flashed her cleavage in the billowing dress, which fell off her shoulders and cinched in her waist.
The gorgeous garment was embellished with white flowers, giving the black dress a touch of colour.
Posing with her hands on her hip, the beauty gazed into the distance with a huge smile on her face.
Amanda’s blonde locks were swept up into a neat updo and she wore stunning bronzed make-up to enhance her good looks.
She captioned the sizzling snap: “Let’s do this! LIVE Semi-Final day 4.
“Last night was incredible, tonight there are some amazing performers coming to your screen on @ITV!!”
Many of Amanda’s 1.1 million followers were blown away by her eye-popping look as they left compliments on the comment section.
One person praised: “Wow what a dress, brilliant!!”
Another gushed: “Oh my god I’m obsessed with this outfit!!”
A third added: “Woahhhh. I’m blinded by this gorgeous look!!”
Amanda’s co-star, Alesha Dixon, 40, also looked phenomenal once again this evening.
The star, who announced she is pregnant with her second child on Monday’s episode, showed off her blossoming bump in a glitzy pink frock.
