Minnesota United and the Chicago Fire netted five goals within a 20-minute span, before the real weather delay went into effect.
Fans took cover on the concourse, with a half-hour to contemplate what had just transpired.
Bongokuhle Hlongwane's play was nothing short of marvelous, but the Fire's second-half substitutions of Xherdan Shaqiri and former Loon Kei Kamara overshadowed the Loons midfielder's second brace in as many Leagues Cup matches. Chicago just needed to hold on for seven more minutes of regulation, plus extra time.
Once the storm settled, the Loons failed to find an answer, though they guaranteed a round of 32 appearance despite their 3-2 defeat. The tournament's group stage lasts through Monday, when Chicago plays Club Puebla. Minnesota's chances of hosting a knockout match depend on that game's result.
An excessive heat warning was accompanied by a severe thunderstorm watch ahead of Thursday's match at Allianz Field.
"I thought we had the game in our hands, but we couldn't protect what we have," Hlongwane said.
It didn't take long for the Loons' 1-0 lead, which Hlongwane initiated off a soft setup pass by Hassani Dotson, to become all but history when Kamara and Shaqiri entered in the 66th minute.
Thanks to a Wil Trapp foul against midfielder Brian Gutiérrez in the box, Shaqiri took advantage of the 69th-minute penalty kick — and just like that, Chicago had momentum.