An electrical storm forced fans to flee for cover before Manchester City's friendly against Bayern Munich in Wisconsin, which became a match of 40 minutes per half.
Before both sides emerged onto the pitch at Lambeau Field an announcement was made urging fans to take shelter on the concourse.
A message on the big screen read: "The National Weather Service has indicated a lightning storm is present in the area.
"For your personal safety we ask that all fans seated in the stadium bowl move to the shelter of the concourses in an orderly manner. Thank you for your co-operation."
The match was delayed by 10 minutes before getting under way, but after Erling Haaland opened the scoring with his first City goal after 11 minutes play was swiftly halted due to more storm warnings.
When the teams returned it was decided that they would play two 40-minute halves with a five-minute half-time break, with both sides eager to get away and fly back to Europe after the match.
Weather warnings had been issued for the area around Lambeau Field in the buildup to the game.
A capacity crowd is in attendance the game between the champions of England and Germany - with almost 80,000 fans packing out the iconic NFL home of the Green Bay Packers.
But electrical storms battered the Wisconsin area on Friday night, prompting weather forecasters to send out alerts for thunder and lightning.
Fans from every US state and 19 foreign countries have snapped up tickets - with many of them hoping to see City’s new £51million striker Erling Haaland make his debut against a club that were desperate to sign him.
Officials had been hoping to avoid the worst of the expected deluge and say they have experience in weathering storms.
Fans were told to dress for wet weather - but umbrellas are banned in a stadium that has no roof and is open to the elements.
It is the first ‘soccer’ game to be played at the stadium, which has a narrow playing surface.
Play will be suspended if there is lightning in the area, with fans evacuated from the ground and moved to covered areas until it is safe to return.
