The ladies teamed up for their first live performance together at Britney's home turf, Planet Hollywood, and it was incredible to see the divas duet -- especially with Iggy singing the chorus instead of just rapping throughout the track.
Britney rocked a barely there sheer leather outfit while Iggy went for a silver metallic dress, and they both really went for it with the sexy alien look. As a bonus, their big headset mics reminded us of '90s Brit-Brit, as did their in-sync choreography. (See what we did there?)
It was hard to keep up with everything going on in "Pretty Girls" -- with rollerbladers, light-up jump ropes, disco lights and pyrotechnics making for a fun house-party-in-space vibe.
Dare we say their Billboard performance was even better than their bonkers throwback alien-themed music video?
Watch the killer performance above.