'Smile' singer Lily has already shared photos of her night out, in which she struck a pose in a neon green dress as she took the tube to London's O2 Arena.
But once inside, Lily spotted Liam and stretched over the seats for a quick photo with the 'Kiss You' singer.
Lily posed in a black jumper emblazoned with the words 'surfboard' on the front, which is a reference to Queen B's 'Drunk In Love' single with husband Jay Z.
Liam, who was wearing a red check shirt, is making the most of his free time before 1D kick off their worldwide stadium tour in May.
Captioning the photo, Lily said: "Megalolz."
it's clear that Lily had a pretty good evening dancing the night away to Beyoncé's string of hits. She admitted to fans this morning: "My yonce hangover won't go away."
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Watch Lily's music video for 'Air Balloon' below: