Ospreys coach Lyn Jones says poor goal kicking and inexperience cost his team a famous win at Stade Francais.
The Ospreys feel they could have claimed a landmark win
"Our missed kicks were crucial," said Jones after watching his team control much of the territory and possession in their 27-14 Heineken Cup defeat.
"The same thing happened against Leicester last year, you have to put the kicks over to win the big games.
"We have the right guys but we have to get more experience and get wiser. That takes time, you can't coach it."
We showed glimpses of what it takes to win in France
The Ospreys now lie third in pool three behind Stade and Sale Sharks.
"We have to take maximum points from our double-header with Calvisano in December," said Jones, whose side's next game is against the Australian tourists in Swansea on Wednesday.
"Sale wiped the floor with Calvisano in Italy and we need to do the same to set up an explosive finale to the group in January.
"But Stade was a huge disappointment. We'd prepared well, the guys were up for it and for large periods we looked like the best team.
"But they are a quality side and took the chances when they came."
Neither the Ospreys, Swansea or Neath have ever won a Heineken Cup game in France, and Welsh sides have only ever recorded three victories on French soil in the competition.
"The old adage is that you have to learn from the experience of playing French teams in France, the frustrating thing is we have," said Jones.
The defeat has only made us more determined to get out of this group
Ospreys captain Duncan Jones
"We showed glimpses of what it takes to win there, we know what makes them good and we are getting there but we need to show some more conviction."
Ospreys skipper Duncan Jones was equally crestfallen.
"It was a disappointed changing room," said the Wales prop.
"We feel we stepped up to the mark, but we were made to pay for one or two crucial mistakes.
"But it's all still to play for us in this competition. The defeat has only made us more determined to get out of this group, but we have plenty to work on."