The national side responded with the game’s opening try, a powerful lineout maul bringing them up towards the try-line and loosehead Michael Milne managed to crash over under a pile of bodies. Lansdowne clubman Byrne, the younger brother of senior international Ross, converted for a 7-0 lead.

The Ireland U-20s continued to pose a threat through a series of attacks, although they were denied by a couple of handling errors. Indeed, with Russell continuing to impress when on the ball, Leinster squared things up in the 25th minute.

Russell made ground with another lung-bursting run and chipped over the retreating Irish defence, allowing his Trinity colleague Liam Turner to break forward into space and finish off a very well-worked try. With Kelly receiving treatment, Russell took the routine conversion and slotted it over.

It was turning into a frenetic contest with both sides willing to commit numbers in attack. The Ireland U-20s pressed from a series of five-metre drives just past the half hour mark, with Casey then moving the ball out to Byrne and Sean French who sent full-back Jake Flannery over in the right corner.

The Shannon star’s try went unconverted, and Leinster got back on level terms before the interval thanks to a similar attacking move at the Bective end of the ground which resulted in an unconverted score for winger Adam La Grue, who played for Terenure College in the All-Ireland League last Saturday.

As expected, the respective benches were unloaded as the second half progressed. The Ireland U-20s resumed in determined fashion with Ulster Academy centre Stewart Moore haring towards the try-line after intercepting a Kelly pass. It took some brilliant defence to hold him up at the expense of a five-metre scrum.

The province’s resistance was broke in the 50th minute, McNamara’s charges keeping up the pressure before out-half Byrne grounded the ball despite the presence of two defenders. After receiving some treatment for a knock, the try scorer converted for a 19-12 scoreline.

The nip-and-tuck nature of the game continued with Leinster almost replying with a spectacular try courtesy of Kelly’s creative spark. His cross-field kick out to Turner was brilliantly weighted, but the former Blackrock College student knocked the ball on with the line in his sights.

As it transpired, the Ireland U-20s pushed on during the final quarter to take the spoils in clinical style. Fifteen minutes from the end, Shannon scrum half Casey raced through a gap to release Buccaneers’ Niall Murray to score his side’s fourth try of the afternoon.

Replacement Jonathan Wren inflicted further damage to the Leinster defence with an outstanding finish for try number five, just two minutes later. After hitting the woodwork with an earlier kick, Byrne added the extras to bring his tally up to 11 points.

A spirited Leinster fired back in the closing stages when replacement Cian Prendergast touched down at the end of an extended move, but the Ireland U-20s had the final say to round off an encouraging display. UCC back rower John Hodnett carried powerfully to get in under the posts with Byrne landing his fourth conversion.

IRELAND UNDER-20: Jake Flannery (Shannon/Munster); Angus Kernohan (Queen’s University/Ulster), Sean French (Cork Constitution/Munster), Stewart Moore (Malone/Ulster), James McCarthy (UL Bohemians/Munster); Harry Byrne (Lansdowne/Leinster), Craig Casey (Shannon/Munster); Michael Milne (UCD/Leinster), Dylan Tierney (Corinthian/Connacht), Ryan Lomas (Galwegians/Connacht), Bradley Luney (Ballynahinch/Ulster), Charlie Ryan (UCD/Leinster), Niall Murray (Buccaneers/Connacht), Martin Moloney (Old Belvedere/Leinster), John Hodnett (UCC/Munster).

Replacements used: Billy Scannell (Young Munster/Munster), Josh Wycherley (Young Munster/Munster), Tom Clarkson (Dublin University/Leinster), JJ McKee (Ballymena/Ulster), Cian Huxford (Corinthians/Connacht), Colm Reilly (Buccaneers/Connacht), David Hawkshaw (Clontarf/Leinster), Iwan Hughes (Ballynahinch/Ulster), Conor Phillips (Young Munster/Munster), Jonathan Wren (Cork Constitution/Munster).

LEINSTER DEVELOPMENT: Robert Russell; Adam La Grue, Ollie Morris (IQ Rugby), David Ryan, Liam Turner; Conor Kelly, Graham Curtis (Malone/Ulster); Giuseppe Coyne, John McKee, Charlie Ward, Grellan Murray, Brian Deeny, Ruadhan Byron, Ronan Watters, David McCann (Banbridge/Ulster).

Replacements used: Harry Noonan, Declan Adamson, Mick McCormack, Cian Prendergast, Adam Flemming, Louis O’Reilly, Stephen Madigan, Luis Faria, Hugo Conway.

Referee: John Lacey (IRFU)