The whole incident was captured on video.
North Park was buzzing with police activity on Wednesday night as hip hop artist XXXTentacion (X) was punched while he was performing on stage.
Police say one person is in serious condition after being stabbed during the disruption.
The incident was captured by cellphones and posted to social media.
X also went on Instagram (NSFW) to rehash what happened, saying that security had set him up.
This was the sixth stop on the singers “Revenge” tour taking place at the Observatory North Park Theatre.
Hip Hop publication XXL Magazine claims that there is a feud between X and rapper Rob Stone who himself jumped on stage earlier this year and punched X’s tour mate Ski Mask The Slump God.
Stone is from San Diego, and many thought that X should steer clear of the city while on his tour.
After the incident, X reappeared on stage looking a little shaken.