The omens had looked positive when Andrew Bishop charged down a Rob Kearney clearance to touchdown after only 19 seconds. Jones converted to give the home side the perfect start to the new campaign. The Wales U21 Grand Slam winner was then at fault for missing an easy three pointer before his counterpart Felipe Contepomi showed him how it should be done to bring the deficit back to just four.
Then from a line-out deep in Leinster territory, Ospreys skipper Barry Williams pushed and pulled to eventually drop over the whitewash for his side's second try and a 14-9 lead. Three Contepomi penalties either side of the interval made it only a two point margin following Lyndon Bateman's yellow card for killing the ball.
Ospreys new signing Leigh Davies then came off the bench to set up another score out wide for centre Bishop. Despite Jones's conversion miss, the game appeared to be won. However, a Girvan Dempsey break and Kearney score swung the match for the visitors.
Contepomi then slotted over what looked to be the winning penalty kick for the visitors before Jones came to the rescue.
B Williams (capt)
F Contepomi (capt)
B O' Meara
Referee: Rob Dickson (Scotland)