19-year-old flanker Scott Penny touched down on his Leinster Rugby debut as they swept the Ospreys aside, winning a one-sided Guinness PRO14 encounter 52-7 at the RDS tonight.

Penny, one of the province’s up-and-coming Academy forwards, scored from a 31st-minute lineout maul with Conor O’Brien and Nick McCarthy also crossing to establish a 24-0 half-time lead.

Captain Scott Fardy and replacements Ed Byrne, Max Deegan and Bryan Byrne took the try tally to seven, with excellent young out-half Ciaran Frawley’s 100% kicking haul seeing him finish with 17 points in a man-of-the-match performance. The Ospreys’ only consolation was a late try from Hanno Dirksen.

As well as it being a night to remember for Penny and the try-scoring Byrne twins, there were debuts in the second half for young replacement backs Jimmy O’Brien and Jack Kelly, who came on for Conor O’Brien and James Lowe respectively during the final quarter.

Both team selections were severely hampered by the November internationals, but Leinster, who absorbed the early pressure, made light of it and stand-in skipper Fardy ghosted through a gap to set up centre O’Brien for an 11th-minute opener.

Three lost lineouts saw Scott Otten’s throw under increasing pressure from Fardy and company, and a high tackle from Olly Cracknell had Leinster hunting for a second try. Frawley and McCarthy were both stopped short before the former landed a 23rd minute penalty.

Further indiscipline from Ospreys invited Leinster forward and from a second maul attempt, Ireland Under-19 international Penny piled over near the left corner. The visitors thought they had scored a well-worked try in response, but James Hook’s score was ruled out for obstruction from debutant centre Johnny Kotze in the build-up.

Fardy was to the fore in a bout of powerful carrying from the home forwards, which led to scrum half McCarthy stretching over for his 37th-minute converted score.

The Conference B leaders had their bonus point wrapped up four minutes into the second half, Lowe making the initial incision before the forwards took over and Fardy managed to touch the base against the base of the right hand post.

A Frawley and Noel Reid-inspired break led to Fardy carrying up lose before Ed Byrne burrowed over to make it 38-0. Adam Byrne gobbled up a Reid kick and fed Deegan, on his inside, to finish off a 63rd minute try from 40 metres out, and Keelan Giles’ try-saving heroics denied Hugo Keenan what would have been a brilliant solo score from deep.

There was still time for Ed Byrne to provide the assist for his sibiling Bryan’s try, with eight minutes remaining. Frawley was unerring with the boot even the outcome well beyond doubt, and the eighth try of the night saw the Ospreys salvage some pride, Sam Davies’ slick pass sending winger Dirksen past two defenders to nip over by the posts.

With his Leinster side now 10 points clear at the top of the Conference B table, following the Scarlets’ home win over Ulster, Leo Cullen said: “Our recent trip to South Africa was actually really good for us, we had a lot of guys away and we actually brought additional players and it was great for them to spend time together away as a group.

“That time together is really important so when they do get that opportunity to play that they’re able to take that chance. They know this is the window for a lot of players and what we encourage them is not to give it up now. This is their window and I thought some guys did really well so it adds to the (selection) dilemma.

“Scott Fardy is very, very important for the team, he’s a very experienced player and adds a lot of energy to the younger guys. Ross Molony has played a lot of games in the second row as well and brings good presence to the group. Michael Bent is invaluable during these periods when we’re missing players.

“The front five laid the platform and I thought guys were clinical and it was a nice and controlled performance for us for the most part. Ciaran, with Noel outside him, he gives him a lot of voice. I thought they combined well. The guys have worked hard, the trip to South Africa was good.

“They worked hard during the course of last week and that set them up well. You could see they were very nervy, it was good they got over (for a try) early on as it gave them confidence. It was a very, very pleasing performance.”

He added: “As long as guys are displaying the right behaviour and they’re working hard, they’re going to get opportunities. It’s going to be a competitive group, we’ve a tough game against the Dragons now next week away and we’re in a massive block of fixtures. Today is the first game of ten in a row with Bath back-to-back, the three Christmas interpros, Toulouse and then Wasps.”