Robert Kearney goes over for Leinster's opening try in Dublin
Leinster: (17) 45
Tries: Kearney (2), O'Driscoll (2), Hickie, Gleeson
Cons: Contepomi (6)
Ospreys: (8) 22
Tries: Cockbain, Terblanche, Pugh
Cons: Connor (2)
Leinster cruised to a convincing bonus-point win over their Magners League title rivals at Donnybrook.
Brent Cockbain's try gave the Ospreys an early lead but Robert Kearney and Brian O'Driscoll touchdowns put Leinster 17-8 ahead at the break.
Leinster surged clear with tries from Denis Hickie, Kearney and O'Driscoll before Stefan Terblanche and Richard Pugh went over to reduce the gap.
Keith Gleeson's try in the final minute sealed a good win for the Irish side.
The Ospreys made a bright start and went ahead after three minutes through a Shaun Connor penalty.
The returning Felipe Contepomi knocked over a levelling penalty but the Welsh side were back in front after 10 minutes.
Jonathan Vaughton broke free and his lay-off found Cockbain, who went over from close range for an unconverted try.
Leinster were lethargic in the early stages but a superb Kearney try on 20 minutes sparked them into life and they dominated the remainder of the half.
The full-back picked the ball up close to halfway and went on a mazy run which saw him escape a number tackles before touching down.
Contepomi added the extra points and the Argentinean repeated the feat 11 minutes later after O'Driscoll surged through for a try following good work from the outstanding Gordon D'Arcy.
Leinster's grip on the game continued after the interval although they were helped by Andy Lloyd's sinbinning on 46 minutes for preventing the Irish side playing the ball.
A rampant Leinster side went on score three converted tries in the next nine minutes.
Hickie went in at the corner after a flowing passing move before Kearney claimed his second touchdown after collecting an O'Driscoll pass.
O'Driscoll completed his own double with a typically powerful run which cut through the Ospreys defence.
With a 25-point lead Leinster relaxed, which allowed Ospreys in for two tries.
Jason Spice set up Terblanche for the first after 66 minutes and Pugh went over from a line-out move four minutes later.
But Leinster had the last say with Gleeson going through the middle for a converted try in the final minute.
Leinster: R Kearney, K Lewis, B O'Driscoll (capt), G D'Arcy, D Hickie, F Contepomi, C Whitaker, S Wright, B Jackman, W Green, C Jowitt, M O'Kelly, S Keogh, K Gleeson, J Heasliip. Replacements: R Corrigan, H Vermaas, O Finegan, T Hogan, G Easterby, J Sexton, R McCarron.
Ospreys: Stefan Terblanche; Jonathan Vaughton, Tal Selley, Andrew Bishop, Richard Mustoe; Shaun Connor, Martin Roberts; Paul James (capt), Ed Shervington, Andrew Millward, Brent Cockbain, Michael Powell, Lee Beach, Richard Pugh, Andy Lloyd.
Replacements: Barry Williams, Adam Jones, Chris Martenko, Ben Lewis, Jason Spice, Nikki Walker, AN Other (back).
Referee: Malcolm Changleng (SRU)