The beat was thumping and the beauty was on fire when Nicki Minaj and Justin Bieber took the stage Sunday night (November 18) to perform their hit duet "Beauty and a Beat" at the 40th annual American Music Awards.

Both performers were up for multiple awards at the show — Nicki led the nominees alongside Rihanna with four nods, while Justin followed closely behind with three —and they proved it with an electric performance. Bieber showed off his signature swag with an army of dancers by his side before Nicki— in all black and a bigger-than-life fro — joined him onstage to show off her God-given flow.

For fans who know the contagious song word by catchy word, there's no doubt they were waiting for one particular line from Nicki: "I gotta keep my eye out for Selena." And she delivered it shamelessly. (Maybe she hadn't heard the rumors that Bieber and longtime girlfriend Selena Gomez had split up just a week before.)

The fiery performance followed uncharacteristically low-key performances from both singers. Directly before breaking out into "Beauty and a Beat," the Biebs gave a heart-melting, acoustic rendition of "As Long As You Love Me." Without his usual team of backup dancers and strobe lights, he sang this one sitting down, accompanied only by a guitarist. The stripped-down performance showed off the star's vulnerable side as he earnestly sang, "So I know we got issues baby/ But I'd rather work on this with you / Thank to go ahead and start with someone new."

As for Nicki, the usually eccentric performer opted for a more subdued version of her track "Freedom." Ditching her signature neon and exorcisms, she strolled peacefully through a winter wonderland, donned in all white, as she showed off the rap expertise that earned her the award for Favorite Hip-Hop Album. Instead of her usual backup dancers, she was joined by a choir to close out a performance that may be one of her most earnest yet.

What did you think of Justin Bieber and Nicki Minaj's performances? Leave your comment below!