Bohemians will need to overcome a first-leg deficit if they are to continue their European adventure.
A goal just before half-time gave Latvian side FK Riga the edge in their Intertoto Cup second-round first leg match - played in front of a sparse crowd in Liepaja, around 200 miles from the country's capital.
In the first half, Glen Crowe had the Gypsies best chance, shooting wide after 25 minutes - but the eircom League side lost midfielder Jason Byrne to a hamstring injury soon after.
The Riga goal came on 44 minutes when, under pressure, the visitors failed to clear the ball which rebounded out to Valerijs Leonovs, who slotted home.
Brian Murphy made two good saves after the break as Riga finished strongest - but Pat Fenlon's team will believe they can overhaul the deficit in Saturday's return at Dalymount Park.
