Police say a 43-year-old Vancouver man lit the flare in the second level seating area and allegedly placed it under an unoccupied seat around 6 p.m. PT on Saturday.
The flames were quickly extinguished by security, but a number of fans suffered breathing difficulties as a result of the flare's smoke.
One woman was transported to hospital for further treatment and has since been released.
Shortly after the incident, security found the man in his seat and he was arrested.
He is facing charges of mischief, criminal negligence and common nuisance, and is expected to appear in court on Monday.