Benetton will contest their first cross-border cup final after Saturday's Pro14 Rainbow Cup game at Ospreys was called off because of three Covid-19 cases in the hosts' camp.
The Italian team will be awarded four points, taking them above leaders Glasgow in the European teams' table.
Glasgow and Munster were in contention, but can not now catch Benetton.
The Italian side will represent the northern league against a South African side on 19 June.
Glasgow were top of the table on 19 points, but have played their allocated five games.
The Scottish side were one point ahead of Benetton, while Munster would have been in contention to top the table if they had won their final match against Zebre in Italy on Saturday.
Benetton are the only unbeaten side in the tournament with four victories and those four extra match points from the Ospreys game being called off will take them top with a tally of 22.
This comes after a regular season when Benetton lost 15 out of 16 games with one draw. The Italians will now host the top South African side in the Pro14 Rainbow Cup final on 19 June.
The Bulls top the South African league and only need two match points against the Sharks on Saturday to seal their place in the final.
Pro14 organisers confirmed the cancellation, adding in a statement: "As a result of the cancellation, Benetton Rugby have qualified for the Guinness Pro14 Rainbow Cup Final on June 19.
"Ospreys Rugby are working closely with Public Health Wales (PHW) following the latest round of Covid-19 testing at the club, which returned three positive results.
"The decision to cancel the game is a result of the mandate from PHW that individuals who were part of the travelling party from the previous fixture are now required to self-isolate in-line with public health protocols.
"With no available weekends remaining, the game will not be rescheduled. As a result, Pro14 rugby will use the protocol decided prior to the 2020-21 season whereby a game that could not be reschedule would result in that fixture deemed a 0-0 draw, but four match points would be awarded to the team who had not been the cause of the postponement.
"In this case, Benetton will receive four match points. This protocol ensures that no artificial scoring points were added to the tries/points for and against columns.
"Adding four points to Benetton's current total of 18 will provide the Italian team with a final standing of 22 points."