Seems most fans at Super Bowl LVIII were on their best behavior Sunday ... because TMZ Sports has learned only six people were arrested at the big game in Sin City.
Cops tell us ... one fan at Allegiant Stadium during the Chiefs vs. Niners tilt was thrown behind bars for grand larceny. Another was booked for battery on an officer. Two others, police say, were arrested for obstruction.
There were also several medical emergencies during the game ... cops tell us they received 56 calls regarding health scares -- adding that nine total people needed to be transported to the hospital for further evaluation.
Outside of that ... the game went off without a hitch -- as the Chiefs won a thriller in overtime, 25-22.