Club America players were tested before leaving Mexico on Monday and wore surgical masks on the plane, the AP reported. Hand sanitizers were installed outside of restrooms, near concession stands and ticket booths, and in the locker rooms.
The game marked the first time Fire's Mexican star Cuauhtemoc Blanco played against his former club in a Chicago uniform.
Club America opened scoring with a goal from Juan Carlos Silva in the second minute and in 42nd its captain, Pavel Pardo, added another with a 20-yard free kick.
Chicago's goal came from Chris Rolfe, who beat goalkeeper Armando Navarrete in the 73rd minute.
Fire goalkeeper Andrew Dykstra saved Salvador Cabanas's penalty kick in the 61st minute.
All Mexican league games next weekend are being played behind closed doors because of the Swine Flu threat.