Eight people were arrested and several police officers were injured in the two-hour melee, the Los Angeles Times said Monday.
Witnesses watched in shock as a mob from the surfing event took their rage to Main Street, where police confronted them with riot gear and tear gas.
Bert Etheredge, who owns a Huntington Beach bike store, said that members of the community stepped in to help him save his shop.
"We were just trying to push people back, just to try to save the shop from people getting in and taking over the shop. You have to stand your ground sometimes," Etheredge told NBC Los Angeles.
We saw some of the locals coming out of the crowd to line up around the shop and tell people to get back. It made me feel better when I was standing up in the window. It's good to know we have a strong sense of community around here.
Lt. Mitchell O’Brien told CBS Los Angeles that it had been "years" since the police department had seen a disturbance that big.
Check out photos of the unrest below:
Huntington Beach pic.twitter.com/Oo4AcstxCi— Pertinax Animus (@PertinaxAnimus) July 29, 2013