Joined by husband Jay Z, Beyoncé attended the 'Never Stop Never Settle' bash in the Big Apple and caught up with Kelly, as well as dancing the night away with guests such as Mark Ronson, Jermaine Dupri and rap star Nas.
Queen B kept her look simple and low-key for the evening, teaming a black beanie hat with a cosy, khaki jacket.
She also switched up the short bob hairstyle she was seen with at the Grammys for long blonde hair extensions and completed her flawless face of make-up with a dark red lipstick.
Meanwhile, her hubby Jay Z also went for a casual ensemble and matched his superstar wife with a black beanie of his own.
Inside the Spring Studios party venue, Kelly wowed guests by taking to the stage with fellow R&B songstress Fantasia and singing tracks from her fourth album Talk A Good Game.
And it seems like beanies were the favourite dress code of the night, since 32-year-old Kelly also sported a black version for her performance, as well as an oversized jersey and a pair of thigh-high leather boots.
Perhaps her sporty outfit was inspired by the Super Bowl football game that took place last night too?
After the fun-filled event came to an end, Kelly tweeted: "Thank you @HennessyUS & everybody that came out!! It was So much fun performing songs from #TalkAGoodGame and celebrating the Big Game!"
No doubt it was a treat for Beyoncé to have an evening off yesterday (2 February) and to support her singing sister, as last year the 'Drunk In Love' star was at the Super Bowl herself, making her show-stopping comeback to the music scene.
Beyoncé famously performed at the 2013 Super Bowl Halftime Show after a quiet year away from the spotlight taking care of her daughter Blue Ivy.
And she reunited on stage with Kelly and third Destiny's Child member Michelle Williams too.
But the girls looked like they had just as much fun in New York last night - particularly Beyoncé, who couldn't resist pulling a funny footballer pose during the celebrations.
What do you think of Kelly's performance outfit? Let us know, as the best comment from across the website each week wins £50!
Got an iPad or iPhone? Reveal Mag has been especially designed to fit!