FC Copenhagen went into the match as big favorites, but they were given a warning of what was to come after just four minutes when keeper Dominik Kotarski was forced to produce a fine foot save to prevent Jens Martin Gammelby from giving the home side an early lead.
But after 27 minutes, Kotarski was left helpless when Callum McCowatt searched into the box to get on the end of a pinpoint pass and steer it past Kotarski for a 1-0 lead.
The opening goal visibly shocked Jacob Neestrup's side, who really struggled to settle into their usual stylish stride at the artificial pitch in Silkeborg. And just two minutes after the opening goal, the home side doubled the lead when Younes Bakiz was left completely unmarked in the Copenhagen box to finish off a superb Silkeborg attacking build-up and put the home side solidly in control.
Shortly before the break, Gammelby tripled the lead when he shook off the challenge of Marcos Lopez to lift the ball coolly over the advancing Kotarski to send the Silkeborg faithful into raptures.
Neestrup's men came out determined after the break to dig themselves back into the match and fashioned a host of chances within a short amount of time. The visitors also claimed a lifeline after an hour's play when Viktor Claesson reduced the deficit from a strong delivery from Viktor Dadason.
FC Copenhagen also dominated the rest of the game and had chances to really bring excitement back into the match, but the home side held on for a famous win.
