Some 300 firefighters and emergency personnel fought the blaze, which began at 8:30 p.m. and consumed three-quarters of the antiquated two-story commercial complex. More than 500 sales "booths" were affected, city officials confirmed.
The blaze started in the "restaurant area" in the upper level of the market, part of which collapsed in the intense heat. Three firefighters were treated for smoke inhalation.
No other injuries were reported.
As news of the fire broke, many stallholders raced to the city center, some of them still dressed in their pajamas. A police cordon kept them 300 meters away from the burning building.
Firefighters contained the blaze at 3 a.m.
Authorities would not confirm what caused the fire although many stallholders speculated that an electrical short-circuit was probably to blame.
A quick-thinking night watchman closed the market's gas valves as soon as he became aware of the fire, a police official said.
The sprawling market spans an entire block and is situated two blocks from the Metropolitan Cathedral and City Hall. It is used by more than 20,000 shoppers each day. Most of the stall holders hawk food, flowers, household items and clothes.
While firefighters were still battling the blaze, Guadalajara city council's opposition National Action Party (PAN) sent out a press release noting that it has consistently highlighted the substandard maintenance carried out in local markets and demanded an immediate investigation.
Guadalajara Mayor Ramiro Hernandez promised to "support" all concessionaires in the market whose businesses had been damaged in the fire.