Any game in the knockout stage that was undecided by the end of the regular 90 minutes, was followed by up to 30 minutes of extra time (two 15-minute halves). For the first time in a major football competition, the golden goal rule was applied, whereby the match would immediately end upon either team scoring during the extra time period and the goalscoring team being declared the winner. If scores were still level after 30 minutes of extra time, there would be a penalty shoot-out to determine who progressed to the next round. As with every tournament since UEFA Euro 1984, there was no third place play-off.
The top two placed teams from each of the four groups qualified for the knockout stage.