It was the French outfit who beat Leinster in last year's quarter-finals, 29-14 - Jordi Murphy's try 20 minutes from time not enough to spark a memorable comeback.
Toulon then went on to beat Munster 24-16 to reach the final but had to rely on the boot of Jonny Wilkinson to edge a tight encounter, in which Ireland winger Simon Zebo grabbed the only try.
And Leinster, who won three European titles between 2009 and 2012, have learnt a thing or two from the Munstermen's showing that day, according to head coach O'Connor.
"It wasn't a lack of ambition last year, I think it was a lack of execution," he said. "There was a lot of intent, probably too much.
"We looked at our game in relation to what Munster went down and delivered in their semi-final and managed the game significantly better than we did.
"We looked at it as a key learning for us that there were execution bits that let us down. It wasn't a lack of ambition. You've got to play. You can't absorb against Toulon. They're too good.
"You've got to play, to execute, to take your opportunities. You've got to make your opportunities first and foremost, and you've got to execute on them.
"The fact that the stakes are so high would give me confidence in relation to the quality of players we've got on the field. If you get the effort and you get the accuracy then I think we're pretty close to where I think we need to be."
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