However, Kvesic produced a big hitting display to win lavish praise from the Sky pundits and admitted after the game he had enjoyed mixing against the best of the Top 14 if not the end result.
"We are bitterly disappointed with the result," he said. "I thought we deserved a little bit more, having had a really good start, but to fair to Stade they came at us in the second half and our indiscipline let us down a little bit.
"We have to try and take the positives from it and look to Parma next week. We will be fit and ready to go.
"Our discipline killed us and (Felipe) Contepomi took his kicks really well. It was tough and we tried to manage the referee, but they played well and deserved the victory.
"It's a huge challenge when you look at what a world class side they have," added Kvesic.
"But it's great to test yourself against them and I enjoyed that if not the result. I will take the positives and it is a learning process for me."