Quins became only the second side in European history to win in Limerick despite being written off by almost everyone bar those within their inner circle.
But while supporters and sections of the media are keen to keep heaping on the praise for the Twickenham outfit, O'Shea's attentions have quickly turned to this weekend's domestic date with high-flying Saracens.
Winning in Munster is one thing, but backing it up with another success a week later would illustrate just how far this young Quins team have come this term.
"It was a great day for the Club and the supporters, but you're only as good as your next game and Saracens is our next job," said O'Shea.
"That's what good sides do: they back it up. They play big games and then come out the next week, play another big game and back it up.
"We've made a lot of positives strides this year in how we're playing the game, how we approach things, the style and the ambition, but you're judged on results at the end of the day.
"Saracens are probably the form side in the Premiership. They're physical and they're well structured and coached.
"They've got a lot of game breakers in the likes of Dave Strettle, who left here last year and is playing great rugby, and Schalk Brits is probably the stand-out player. They've got players all over the park, like Alex Goode, and Owen Farrell also plays good rugby."
Critically, Quins head into Saturday's final league fixture with their European future still undecided.
Currently sitting seventh in the Premiership standings, the 2009 Heineken Cup quarter-finalists know victory over Sarries, coupled with defeat for London Irish at Leicester, would see them return to the continent's top table next season.
And while O'Shea and co have undoubtedly enjoyed the Amlin experience, it's no surprise that they are desperate to be competing for the continent's top prize next time around.
"It's a massive challenge for us, but it's what we want at the business end of the season," added O'Shea.
"You could be drifting into the last league game with nothing to play for, but we've got something to play for this weekend and we've got a final coming up.
"Mentally it's a bit of a challenge because there was a lot of emotion and build up to the Munster game. But it's only a game and it's only a semi-final. We now have a massive game this week.
"We have a lot of young guys in our team, and some of the older guys like Nick Evans and Nick Evans want to be playing in the Heineken Cup. They want to be playing in games like last week, every week.
"We have a chance this week in the Aviva Premiership - if we win and London Irish lose, we've got that Heineken Cup spot nailed. It's out of our control, but at least we have another opportunity in the Amlin Final, which we'll focus on from Sunday."