In a night filled with megastars -- from Jay Z to Usher to Lil Wayne -- Beyoncé and Nicki Minaj probably created the most memorable moment at last week's TidalX1020 concert.

But it's not like they just showed up, unprepared, and performed "Feeling Myself" (together, for the first time, by the way). People's faces probably would have still melted, like they actually did, had that happened. But Bey and Nic are consummate professionals, so they were ready.

Considering how flawless the performance was -- they had a dance off, played off of each other expertly, and alternated whom our attention was focused on -- you know they put in a lot of work behind-the-scenes. And on Monday (Oct. 26), we got a glimpse of some of those preparations.

And that includes a staring contest. "Let's see who cracks first..." Bey wrote on Facebook, along with the video.

IT'S ON.