She also shared her excitement on Instagram, writing: "Missed being on stage. ready for Vegas tonight!"
Spears was just wrapping "Crazy" on August 9 when a yet-to-be-identified individual bypassed security and theater personnel and made his way onto the stage, TMZ reports. They said he was taken to the Clark County Detention Center but as of the time of publication, he was not yet in their database. "There is no further information regarding this arrest and additional information will have to be obtained through the Clark County Justice Court".
Fortunately, the stage invader was apprehended by security and some of Spears' dancers who promptly tackled him to the floor.
A source close to the star told DailyMail.com Britney was terrified during the incident.
Brit was singing (or not singing, the debate is still open on that one) her hit song "Crazy" on the catwalk when all hell broke loose on the main stage. When security approaches her to explain what's going on, she looks real freaked out but in the cutest way possible.
Spears could be heard asking her team, "Is everything okay?"
She then asks with urgency: "He's got a gun?"
The man was eventually handcuffed by guards and detained while Britney was escorted from the stage.
A spokesperson for Spears has not yet responded to TheWrap's request for comment.
It didn't appear as though Spears saw the man, who crept up behind some of her dancers. Facing the crowd, her back was turned to the man. Spears says, her knees buckling.
The moment was captured on video by concertgoers from different angles, and one shows the moment the person was tackled by security guards, before the singer, 35, even realized something was happening.
Britney shared her excitement about performing beforehand.
Some had a more jaded and wry perspective on the night's events, with a concert goer writing: "Chairography".
The "Lucky" singer's Vegas residency "Piece of Me" first kicked off in Dec. 2013 and is scheduled to run through this December.