But while very few pundits were tipping a famous away victory, Quins' young fly-half Rory Clegg and his colleagues were confident they had the ability to leave Limerick with a stunning success under their belts.
"We all know what we're capable of," said Clegg, who guided Quins to glory after Nick Evans succumbed to injury in Ireland.
"We've showed our potential in patches this season, like against Gloucester when we beat them 53-15 at home.
"We've got a lot of flair and a lot of ambition in the squad, we play at a high tempo, and that showed against Munster.
"We said before the match and all week leading up to it that we wanted to start well. In the first 20/25 minutes we really took it to them. We showed them what we can do and I don't think they were expecting it from us.
"We managed to sneak a few tries in, played some really good rugby and probably could have scored a couple more tries if we'd been more clinical.
"We took some people by surprise and I think the people who wrote us off before the match will take us a bit more seriously now."
Victory over former Heineken Cup winners Munster saw Harlequins secure an Amlin Challenge Cup final berth against Stade Francais in Cardiff on Friday, May 20.
Another famous success on the European stage would ensure Quins become the first side to claim a hat-trick of Challenge Cup titles having previously won the competition in 2001 and 2004.
And with confidence in the camp high, Clegg sees no reason why Quins can't be celebrating again in a week-and-a-half's time.
"We said at the start of the season that we wanted to win some silverware. We've put ourselves in a great position to do that," added Clegg, who admitted he was desperate to get off the bench and into the action in the semi-final.
"The boys have beaten Stade Francais before and that will give us a lot of confidence, as will the Munster match.
"Everyone was pretty happy after that Munster game. Everyone was buzzing after that weekend.
"We've said all season that mistakes are going to happen in games - it's just about how we react to them. We did make mistakes against Munster but we reacted in the right way. We got on the scoreboard early and we kept hold of the lead.
"I thought we played really well overall and did well to win it when we were one man down at the end.
"I really wanted to play in Munster. It was unlucky for Nick - no one wants to see someone get injured - but I was really excited to get on. To get 40 minutes was amazing.
"Thomond Park is definitely up there with the best atmospheres around. To go from the nosiest place I've ever played at, to the quietest when you're kicking at goal is pretty amazing."