St Patrick's Athletic dominated for large periods of this UEFA Europa League tie but conceded an away goal and must now score against Valletta in Malta this day week to advance.
Following chances for Dave Partridge, Bobby Ryan and Stuart Byrne, new signing Declan O'Brien fired home from nine yards on 37 minutes.
Valletta equalised on 65 minutes when Gilbert Agius fed the ball to Gijsbertus Den Ouden who returned it to Agius, allowing him to set up a fine shot past the diving Gary Rogers and giving Pat's a tough task next week.
Injury-plagued St Pat's gave a debut to loan-signing O'Brien, while the visitors included one-time Shamrock Rovers player Luke Dimech and former Barcelona and Manchester United star Jordi Cruyff in their line-up.
Pat's had much the better start of the two. Valletta goalkeeper Andrew Hogg did well to stop Partridge's header on four minutes after Alan Cawley played a neat one-two with Ryan Guy from his corner and crossed.
Pat's kept up the pressure as the game continued and Ryan shot just wide of Hogg's right post on 15. Byrne followed that with a drive wide of the other post but O'Brien should have done better when he shot straight at the keeper on 25.
Pat's' good work continued and they took the lead on 37 minutes when a Guy cross arrived in the area from the right wing. With the Valletta defence seemingly static, Garreth O'Connor got a touch before the ball fell to O'Brien who fired home at the post.
Valletta came out fighting for the second half as they went in search of a vital away goal. There was a good deal of grit and determination about them but they were kept at bay by a strong Pat's defence and midfield, with particular standout performances by Partridge, Byrne and Jamie Harris.
The breakthrough for Valletta eventually came on 65 minutes when Gilbert Agius fed the ball in the danger area to Den Ouden who returned it neatly to Agius allowing him to set up a fine shot past Rogers.
Hogg then made a good save from Ryan on 69 before Rogers made an absolutely outstanding save from a Jamie Pace shot at the other end a minute later.
Den Ouden was well placed for a shot on 76 but shot tamely into Rogers' grateful hands, while the same player then collected a decent Agius cross on 81 but fired high over the Inchicore-end stand.