Ariana Grande's 2019 Coachella experience has been legendary, to say the least. After spearheading an NSYNC reunion last weekend, she surprised the audience with another kind of return on the festival's closing night Sunday (April 21) – a special, spur-of-the-moment performance with Justin Bieber.

Grande's surprise guest came out deep into her set as she prepared to move into "No Tears Left to Cry." She slowed things down to make the announcement: "I wasn't going to bring out any guests tonight. But my friend Justin Bieber came all the way out." The crowd erupted into gigantic, earth-shaking roars as he came onstage to sing his signature hit "Sorry." Bieber was a little winded and the energy felt lax, but he acknowledged his rustiness afterward.

Speaking to the crowd, he admitted that the performance was his first in "like two years, so I had to get my groove back, had to get my swag back, you know what I'm saying." As the crowd continued to erupt in the background, Bieber gave Grande his thanks and hinted at a new album coming soon — despite an Instagram post from March that suggested he was taking a step back from music to focus on his mental health.

It was Bieber and Grande's first team-up since appearing on Lil Dicky's all-star collab smash "Earth," which dropped on Friday.

Grande's epic Bieber moment rivals that of last week when she reunited NSYNC (sans Justin Timberlake) to perform "Tearin' Up My Heart" from their self-titled 1997 debut album. In addition to dipping into '90s pop nostalgia, she also leaned into its hip-hop with a performance of "Mo Money Mo Problems" featuring Diddy and Mase. She also performed "Bang Bang" with Nicki Minaj while battling technical problems. But she emerged victoriously.

Take a look of footage of Bieber's surprise performance up above.