The goal-to-goal rule was abolished on Thursday by UEFA after 56 years as the main way to decide matches in its European club competitions.
The move has often been offered in recent years by club coaches, who felt that an idea from the 1960s was no longer relevant.
The games, which are now tied to a total score, after the regulation 90 minutes in the return match will go directly to overtime and then to penalties.
UEFA President Alexander Cheferin quoted “the injustice, especially in overtime, to oblige the home team to score twice when the guest scores a goal”.
UEFA cites several factors that “blurred the boundaries between playing at home and away”, including more television coverage to better understand opponents’ styles, comfortable travel and better playing surfaces.
Cheferin said the rule outlived its usefulness and prevented home teams from attacking, “because they are afraid of conceding a goal that would give their opponents a key advantage.”