Backstreet Boys -- All Five Of Them -- Reunite Onstage In L.A.

Kevin Richardson joins former bandmates for scream-filled 'Shape of My Heart.'

For the first time since leaving the group in 2006, former Backstreet Boy Kevin Richardson joined the rest of the group onstage in Los Angeles Sunday night, on the last stop of their Unbreakable tour at the Palladium in Hollywood.

In a fan-made video that's surfaced online, the audience erupts into deafening screams when Richardson emerges onstage to join the group for "Shape of My Heart," from the group's Black and Blue album. He's seen goofing around with his former bandmates, and at one point even lifts Nick Carter's shirt. The five are very chummy in the clip and seem to be feeding off of the audience's energy; the screams render the first minute of the song completely inaudible in the clip.

A comment by the person who posted the video says: "There was not a dry eye on the audience. We all bawled our eyes out. I couldn't believe right in front of my very eyes I was seeing this."

The group appeared without Richardson during the "TRL" finale earlier this month.

The reunited Boys — Carter, Howie Dorough, Brian Littrell and AJ McLean — told MTV News in October they were skeptical that Richardson would ever come back to the group since he left it to pursue "new goals," but insisted that the door was always open for Richardson to make his return. Dorough added that Richardson is in "such a good place right now," raising a family and pursuing an acting career.

"In the beginning of the tour, we left a gap onstage where Kevin would be, and then it started closing up," Carter said. "We love him to death. We have to move on. We have new goals and dreams."

On Sunday night, Richardson filled the gap himself.