Dundalk beat Sheriff Tiraspol on penalties to move to within 90 minutes of the UEFA Europa League group phase.
Chris Shields struck the decisive spot-kick, after Gary Rogers had set them up for the win by saving from Faith Olibor.
Dundalk on the shoot-out 5-3 and will be at home to the Faroes of KÍ in the playoff round.
The win capped a brave performance away from home by Filippo Giovagnoli's side.
They fell behind inside 8-minutes when Veaceslav Posmac gave Sheriff the lead.
But Dundalk heads didn't drop, and they found their equaliser in first-half injury time.
Sean Murray rose to meet a right-footed Michael Duffy cross from the left. With Zvonimir Mikolic flapping, the net bulged and Dundalk were level.
Neither side could forge many clear-cut chances in the second half, and with legs heavy in extra-time it was left to penalties to decide who'd progress.
While facing a side from the Faroe Islands may set Dundalk tails wagging, they'll face tricky opposition next week.
KÍ secured their trip to Ireland by hammering Dinamo Tbilisi 6-1.
Elsewhere, Son Heung-Min was again the star of the show for a Tottenham side who won 3-1 away to Shkendija of North Macedonia.
The Korean scored one and set up Erik Lamela and Harry Kane for the others. Next up for Jose Mourinho's side is the visit of Maccabi Haifa to the Tottenham Hotspur Stadium.
Celtic were heading for extra-time in Latvia before Mohamed Elyounoussi struck in the last minute to give them a 1-0 win over Riga. They'll be away to FK Sarajevo with a group stage place at stake next week.
Filip Helander netted twice as Steven Gerrard's Rangers won 4-0 away to Willem II. Galatasaray will visit Ibrox in the playoff round.
A battling Aberdeen were beaten 1-0 away to Sporting.
And Motherwell had Declan Gallagher sent off in a 3-0 loss to Hapoel Beer Sheva.