Fire score 3 goals in first 13 minutes, beat Atlanta 5-1
Chicago (5-7-7) snapped a six-game winless streak. Atlanta (9-7-2) had won the previous three meetings in the series.
Calvo opened the scoring in the fourth minute by heading in Gaitán's corner kick, Sapong scored three minutes later on a counter attack and Gaitán converted a penalty kick for a 3-0 lead after Atlanta defender Leandro González Pirez was given a straight red card.
Chicago made it 4-0 in the 37th when Sapong calmly slid it inside the far post on a breakaway and Fabian Herbers sneaked it inside the near post just before halftime for a 5-0 lead.
Brandon Vázquez scored on a penalty kick in the 58th for Atlanta, which played the final 10 minutes with just nine men because of an injury to Dion Pereira.