Republic of Ireland were spared the task of having to beat Denmark by two goals to secure their Euro 2020 place after Switzerland's win over Georgia.
Substitute Cedric Itten's 78th-minute goal edged the Swiss past Georgia in St Gallen as they leapfrogged the Republic into second place in Group D.
With Denmark beating Gibraltar 6-0, a Swiss win over the Iberians on Monday means a win over the Danes will secure qualification for the Republic.
Both matches kick-off at 19:45 GMT.
The only scenario in which the Republic will need to beat Denmark by two clear goals is if Gibraltar hold Switzerland to a draw.