The riot itself began on September 13 of 1922, two days before the supposed unspoken date, when a group of youths decided to get an early jump on the tradition. This group began in the former "Mulberry Bend" area of Manhattan by removing and stomping hats worn by factory workers who were employed in the area. The more innocuous stomping turned into a brawl when the youths tried to stomp a group of dock workers' hats, and the dock workers fought back. The brawl soon stopped traffic on the Manhattan Bridge and was eventually broken up by police, leading to some arrests.

Although the initial brawl was broken up by police, the fights continued to escalate the next evening. Gangs of teenagers prowled the streets wielding large sticks, sometimes with a nail driven through the top, looking for pedestrians wearing straw hats and beating those who resisted. One man claimed that his hat was taken and the group who had taken his hat joined a mob of about 1,000 that was snatching hats all along Amsterdam Avenue.[4] Several men were hospitalized from the beatings they received after resisting having their hats taken, and many arrests were made. Police were slow to respond to the riots, although several off-duty police officers found themselves caught up in the brawl when rioters attempted to snatch their hats.