The Polish club - now managed by ex-Rangers defender, Henning Berg - travel to Dublin for the second leg on Wednesday still rocked after needing a stoppage-time goal to secure a 1-1 draw at home this week.
Waiting for them in the third qualifying round - provided they can finish the job they started against KR Reykjavik on Tuesday - will be Celtic.
And the man who grabbed that all-important equaliser against the Irish, Miroslav Radovic, is confident the Polish champs can not only get through, but prove to be a match for Ronny Deila's side.
He knows all about Celtic as a club, which has a strong Polish connection through the likes of Lukasz Zaluska, Artur Boruc, Dariusz Dziekanowski and Dariusz Wdowczyk. But the Serbian winger reckons the reputation of the Hoops is more frightening than the actual team.
Radovic said: "I'm sure on Wednesday we will beat the Irish and go through to another round. If we play Celtic, I'll be really happy. It's big club, the fans will watch two interesting games.
"We won't be without a chance. Maybe the name of the club is impressive, but the team is within our reach.For now, though, I'm focused on revenge against St Patrick's.
"We must play well to make people forget about the first shameful game in Warsaw."
Berg would be delighted if he could return to Glasgow, this time as a manager.
But he accepts it will take a much-improved performance if they are to book their ticket.
"We're extremely disappointed with the performance in the first leg," said Berg. "The tie is not over, though. It's possible for us to win in Ireland."
However, Celtic assistant manager, John Collins, admits he will be rooting for St Pat's, for logistical reasons if nothing else.
As he flew out with the Hoops for today's friendly against Dynamo Dresden, he said: "It's a good draw but, obviously, we'd prefer to play in Ireland..
"I'm sure they'll be highly motivated to play Celtic in the next round.
"There's no doubt there would be a wonderful atmosphere. But first thing's first, we've got to take care of the second leg against Reykjavik."
The juicy prospect of facing Celtic is certainly acting as an extra spur to St Pat's.
They drew 0-0 at Parkhead when the clubs met in the qualifiers for the 1998-99 European Cup before the Hoops won the return leg in Dublin 2-0.
And club secretary Anthony Delaney can feel the buzz building already with Celtic back on the horizon.
He said: "If it is Celtic, it will be phenomenal because there is a huge Irish-based Celtic support. We'd expect a full house and a huge game."
St Pat's manager Liam Buckley hoped the goal from former Hamilton Accies striker Christy Fagan would give them a lead to take into the second leg against Legia.
But even with the tie level, he remains bullish they can get through and said: "We'd like to think we will qualify. We have a better handle on the way Legia play. I hope that will help us next week."