Surprise! Lizzo turned the TMZ Brunch Bus into a rolling concert Sunday … hyping up the crowd and performing like the party was headed straight for Coachella instead of cruising through the streets of Los Angeles.

Check out the video … the hitmaker looked totally in her element — belting some of her biggest hits during the ride while dancing through the aisle … as passengers screamed and waved their hands in the air.

Wearing a colorful zig-zag top and oversized shades, the Grammy-winning artist had the entire bus rocking as passengers belted out every word alongside her. The bus was packed wall-to-wall with everyone filming, dancing and singing along … while Lizzo turned all the way up.

The ride was emceed by influencer Javonte Rosello … and VOX DJs kept the music blasting throughout the ride — helping keep the energy high throughout.

And the intimate setup made the whole thing feel even crazier … giving fans a front-row view of Lizzo just a few feet away as the bus rolled through L.A. At one point, the party made a pit stop for shots … before everyone piled back on the bus and kept the celebration going.