|Pro14: Ospreys v Leinster|
|Ospreys (10) 13|
|Tries: Morgan Cons: Price Pens: Price 2|
|Ulster (7) 21|
|Tries: O'Brien, Murphy, Kelleher Cons: Crawley 2, Byrne|
Leinster kept their unbeaten season going with a 21-13 victory over struggling Ospreys at the Gnoll.
It was a 12th successive Pro14 win for the Irish province and an 18th victory of the season.
Tries from Tommy O'Brien, Josh Murphy and Cian Kelleher clinched the win, while Ospreys responded with a Luke Morgan try and eight points from Luke Price.
Leinster's victory took them 19 points clear in Conference A.
Ospreys continue to prop up this section with just two wins in 12 league matches this season.
Ospreys had Wales pair Owen Watkin and Adam Beard starting again while there was one change from the side that defeated Ulster and halted a four-month losing sequence.
Number eight Dan Baker replaced Gareth Evans while flanker Olly Cracknell made his 100th appearance for the region.
Leinster made eight personnel changes and one positional from the side that beat Cheetahs with Rhys Ruddock moving to number eight.
James Tracy replaced Ireland squad hooker Ronan Kelleher while Australian lock Scott Fardy captaining the side.
Fardy gave the scoring pass to Leinster replacement O'Brien to open the scoring with fly-half Ciaran Frawley converting.
Centre Kieran Williams almost claimed the hosts' first try with a scything break down the left hand corner before being dragged down just short with the ball going forward and wing Morgan denied the try.
Price opened the Ospreys scoring just before half-time with a penalty and Morgan quickly crossed for the first try after capitalising on a Leinster mistake.
Visiting centre Leinster centre Jimmy O'Brien and wing Cian Kelleher missed the tackle on Morgan who sprinted away to score.
Price converted as Ospreys led 10-7 at the break.
Leinster regained the lead after a series of scrum penalties. Ruddock, playing against the region where his Dad Mike is now performance director, charged just short of the line before flanker Murphy burrowed over. Frawley converted.
Centre Williams launched another surging run before receiving a stray boot from his own player Sam Cross which forced him off the field temporarily before he passed a head injury assessment. Price slotted over a second penalty to reduce the deficit to a point.
Ospreys were reduced to 14 men with replacement hooker Sam Parry yellow carded for a professional foul. Leinster took advantage of their numerical superiority with a simple try for Kelleher with Harry Byrne adding the conversion and denying Ospreys even a losing bonus point.
Ospreys coach Carl Hogg told BBC Wales Sport:
"It's frustration really after a game of two halves with the elements the way they were.
"First half we didn't get enough on the scoreboard with the elements behind us and we didn't take two or three clear-cut chances while Leinster were very clinical, and the scrum was a dominant aspect for them.
"It's been a challenging period of time in Ospreys history but the group's very positive, defensively it was probably one of our best displays of the season, and Kieran WIlliams in the centre got us on the front foot.
"There's a lot to be positive about, (for next season) a fully fit Ospreys squad is a very strong squad."
Leinster director of rugby Leo Cullen told BBC Sport Wales:
"Conditions were always going to be tricky, we scored a good try but we were very inaccurate in that five minutes before half-time.
"We started the second half with some sustained pressure and the scrum was an important weapon. It was far from perfect from us, we're delighted with the win but we need to be better in future.
"(Ex Wales forwards coach) Robin McBryde is settling in well, he has so much experience and he's a great character for us to have as well.""
Ospreys: C Evans; H Dirksen, O Watkin, K Williams, L Morgan; L Price, A Davies; N Smith, S Otten, S Gardiner, A Beard, B Davies, D Lydiate (capt), O Cracknell, D Baker.
Replacements: S Parry, G Thomas, G Gajion, L Ashley, S Cross, S Venter, T Thomas-Wheeler, J Hook.
Leinster: H Keenan; C Kelleher, J O'Brien, C O'Brien, J Lowe; C Frawley, J Gibson-Park; P Dooley, J Tracy, M Bent, R Molony, S Fardy (capt), J Murphy, S Penny, R Ruddock.
Replacements: S Cronin, M Milne, J Aungier, J Dunne, R Baird, R Osborne, H Byrne, T O'Brien
Referee: Stuart Berry (SARU)
Assistants: Aled Evans (WRU), Ben Breakspear (WRU)
TMO: Tim Hayes (WRU).