The result atoned for last week’s 10-21 defeat to Toulouse at the Twickenham Stoop and has left Harlequins just one point behind the French giants but O’Shea knows his side need to build on yesterday’s result in the remaining two games to ensure qualification to the knockout stages.

"Right now this feels like we've won a cup final but it's a pool game and we have to make sure we keep learning,” he said.

"The resolve the players showed was incredible. We have a good record away from home but we knew coming here we were going to have to ride our luck at times in the face of wave after wave of pressure.

"They missed a couple of kicks but we had the ambition to play and everyone involved with Harlequins must be very proud of the effort of the players.

"We won't stick our heads in the sand and say it was a perfect performance but these are the days that make the Heineken Cup and the games you are judged on."

A home game against familiar opponents Gloucester and a visit to Connacht’s Sportsground need to be navigated before O’Shea’s team can think about the knockout stages but the Limerick man knows that if Harlequins can replicate yesterday’s performance they’re in with a fighting chance.

“We have shown how quickly we can learn at this level. We were disappointed with a few things from the previous game at the Stoop but we got our line-speed in defence right and that pressured them into mistakes.

"When you look at their bench, they were bringing on more power after power but when you're in the match, you get carried away with adrenaline and that's what happened here.

"We got a few breaks and then Tom Williams came off the bench and produced a game-changing moment that got us right back into the game when we needed it most. Then we held out for a big result."