Scarlets skipper Jones saw Sean Lamont and Phil John reply with tries in either half to sink the reigning Heineken Cup champions.
But the Wales wing insists it is far too early to doubt the Magners League title hopes of Leinster and rivals Munster who lost to Glasgow.
Jones, 29, said: "I'm sure both Leinster and Munster will bounce back. Those teams have quality players and are missing their British Lions at the moment.
"I'm sure for their depth that it will be good for them to develop. You don't usually see a lot of their internationals this early in the season anyway because of the way the Irish provinces work.
"Of course, it's great to beat the European champions because we're hearing great things about their development policy and the players who will replace the O'Driscoll's and Gordon D'Arcy's are no mugs.
"But we showed tremendous character against a really good team with a great pedigree.
"It is early days but I'm sure it will be a scrap for the play-off spots this season and we know the Irish teams will be really strong come Christmas."