Ospreys had their unbeaten start to the PRO12 season ended at the hands of Leinster as Jonathan Sexton scored in their 31-19 win.
By the time the whistle was sounded at the break, Ospreys were already well and truly out of the running of making it four wins from four.
Three first-half tries had put Leinster firmly into the driving seat. Josh van der Flier, Sexton and a penalty try formed a 24-0 lead at the break, with Ospreys' opening victories seeming a long time ago. Another Van der Flier try secured the bonus point.
Leinster did strike three times in the second-half through Ben John, Dafydd Howells and James King as they searched for a bonus point, but it proved to be in vain as the hosts ran in 31-19 victors.
It was a far cry from the three bonus-point wins that had seen Ospreys produce a perfect start to the campaign, with the hosts dominating from the off.
Sexton kicked Leinster ahead seven minutes after an infringement at the line-out, with tries following soon after.
Van der Flier started the demolition inside the first 20 minutes, coming immediately after a line-out. The Welsh side dragged a maul down, but a fortunate series of advantages from the official saw the flanker step over and ground. Sexton, on his first game of the campaign, saw his conversion make it 10-0, with the hosts on top early on.
Ospreys did have opportunities to get themselves on the scoreboard, but a yellow card midway through the first 40 turned the game firmly in Leinster's favour. Dimitri Arhip was sin-binned for a clumsy challenge, coming after a series of warnings for technical offences. That spelt real danger for Ospreys, and Leinster took full advantage of the extra man.
The visitors were penned firmly inside their own 22 for a significant amount of time, and with no way out, a penalty try was the only option after Ospreys collapsed a drive for the line. Sexton was allowed the easiest of conversions from right in front of the posts, making it 17-0.
And though that would have been almost manageable, Ospreys were given little chance of recovery as try three was clocked right on the break. It was the final play of the half that saw Sexton following his impressive kicking with a try. A counter-attack was reversed, with a lightning fast counter seeing a four on two attack emerge, with the number 10 touching down.
The conversion followed, as did the bonus point after the break. That point came only six minutes into the second 40, Van der Flier grabbing his second of the night. Some weak challenges came flying his way, but he easily batted them away, making the most of Sexton's good work. The latter converted, the bonus point arrived and a 31-0 lead truly finished the tie off.
Ospreys were invited into the game as the hosts rang the changes, and they grabbed their first try through John. He slid over in the corner after coming in with the overlap, but Dan Biggar struck the upright as he failed to add the extras.
Sexton was sin-binned minutes later, and that was the catalyst for an Ospreys rally that put a bit of fear into the hosts and some competition into the scoreline.
Howells grabbed number two with 10 to play, Biggar delaying a pass before sending the pass into the replacement's path. Biggar converted, and did so again after King crossed.
Sam Davies deceived the Leinster defence, skipping challenges before laying possession off to King who went over unchallenged. Biggar converted, with the deficit cut to 12 at the end.
Tries: Van der Flier 2, Penalty Try, Sexton
Cons: Sexton 4
Tries: John, Howells, King
Cons: Biggar 2
Leinster: 15 Zane Kirchner, 14 Isa Nacewa (c), 13 Garry Ringrose, 12 Noel Reid, 11 Dave Kearney, 10 Johnny Sexton, 9 Luke McGrath, 8 Jamie Heaslip, 7 Josh van der Flier, 6 Jordi Murphy, 5 Mick Kearney, 4 Devin Toner, 3 Tadhg Furlong, 2 Sean Cronin, 1 Cian Healy
Replacements: 16 James Tracy, 17 Jack McGrath, 18 Mike Ross, 19 Ross Molony, 20 Rhys Ruddock, 21 Dan Leavy, 22 Jamison Gibson-Park, 23 Joey Carbery
Ospreys: 15 Sam Davies, 14 Jeff Hassler, 13 Ashley Beck, 12 Josh Matavesi, 11 Ben John, 10 Dan Biggar, 9 Rhys Webb, 8 Tyler Ardron, 7 Justin Tipuric, 6 James King, 5 Alun Wyn Jones (c), 4 Lloyd Ashley, 3 Dmitri Arhip, 2 Scott Baldwin, 1 Paul James
Replacements: 16 Sam Parry, 17 Nicky Smith, 18 Ma’afu Fia, 19 Bradley Davies, 20 Dan Baker, 21 Tom Habberfield, 22 Dafydd Howells, 23 Dan Evans
Referee: Marius Mitrea (Italy)
Assistant referees: Matteo Liperini (Italy), Stuart Gaffikin (Ireland)
TMO: Carlo Damasco (Italy)