Sweeney makes his debut for Leinster u20's
- 1815
It was impossible to forecast with any degree of confidence the likely outcome of a new format.
Leinster's first thought was to move the ball for scrum-half Charlie Rock's Garryowen to be taken in by prop Jeremy Loughman.
From there, the ball was shifted with purpose for serious gains down the left with Munster dealing well with two crossfield balls from Conor Dean and Jimmy O'Brien.
The Munster counter ideas were based on putting the ball in the air for wing Lee Molloy to claim the first and the second to cause a penalty for holding on by Jack Kelly for fly-half Alan Tynan to shave the right upright.
Leinster hooker Conor Maguire was immediately whistled for playing the ball off his feet. Tynan made no mistake from 30 metres for 3-0 in the eighth minute.
Then, referee Joy Neville red carded Murphy for a reckless kick in the ruck.
A pair of penalties at the breakdown went the way of the home side for Dean to put Leinster in business. Jack Regan gathered the lineout only for flanker Alan Fitzgerald to execute a turnover.
Prop Rory Burke stepped into Kelly to concede a penalty. Dean went for the corner flag.
The maul was activated and Kelly came on the blindside for a try to make good on their sustained pressure with Dean converting to make it 7-3 in the 17th minute.
The Munster scrum churned out a penalty. But, the non-stop work of Will Connors ruined their maul.
Not for the first time, Jimmy O'Brien's hands put an attacker into space, this time Jordan Larmour, and Jack Power was a fingertip away from collecting Dean's ball over the top.
Munster tight-head Burke earned another penalty at the scrum. Tynan made it a one-point game in the 25thminute.
Leinster went straight back into attack mode, Dean's angled punt brilliantly taken in by full-back Colm Hogan.
The fine footwork and hands of flanker Gavin Combes and work rate of prop Joey Conway came to nothing five metres out due to a knock-on.
Munster were beginning to edge the battle for territory through their breakdown work and Leinster's indiscipline for Tynan to make it 9-7 in the 38th minute.
The home side hit back when Loughman was put through by scrum-half Charlie Rock's wide pass and Dean flipped the ball to Larmour for 12-9 at the break.
Leinster were quickly out of the blocks. Will Connors broke the line for front-foot ball that was turned into three points by Dean's penalty in the 45th minute.
The Munster scrum made hay once again without a tangible reward.
It took exquisite interplay between Larmour and Kelly for the latter to finish into the right corner to make it 20-9 in the 56th minute.
Then, Kelly came steaming through the middle to draw in Hogan for Ciaran Frawley to cruise over and convert for 27-9 on the hour.
The improvement in Leinster's scrum took away their visitors' main weapon of destruction.
Prop Oisin Heffernan pinched a penalty on the floor for Frawley to apply pressure again without the finish to match it.
A rare break out by Munster was concluded by a try from second row Fineen Wycherley which was converted by Conor Fitzgerald in the 72nd minute.
This was immediately countered by a rapid response unit, led by Larmour, for Heffernan to ground at the posts. Frawley's extras made it 34-16 in the 75th minute.
The Larmour-Kelly double act was harnessed again for Gavin Mullin to close it out at the final whistle.
At Donnybrook: LEINSTER 39 (J Kelly 2 tries; C Frawley try, 2 cons; J Larmour, O Heffernan, G Mullin try each; C Dean pen, con); MUNSTER 16 (F Wycherely try; A Tynan 3 pens; J Fitzgerald con).
LEINSTER: Jack Kelly (St Michael's College, Capt); Jordan Larmour (St Andrew's College), Gavin Mullin (Blackrock College), Jimmy O'Brien (UCD), Jack Power (Clontarf); Conor Dean (Blackrock College), Charlie Rock (Old Belvedere); Greg McGrath (Lansdowne), Conor Maguire (Old Wesley), Jeremy Loughman, Jack Regan, Josh Murphy (all UCD), Caelan Doris (Blackrock College), Will Connors (UCD), Paul Boyle (Lansdowne).
Replacements: Max Deegan (Lansdowne FC) for Boyle 51 mins; Óisín Heffernan (Terenure College RFC) for McGrath 53 mins, Hugo Keenan (UCD RFC) for Power both 53 mins; Ciarán Frawley (Skerries RFC) for Dean 56 mins; Tadgh McElroy (Lansdowne FC) for Maguire 60 mins; Barry Fitzpatrick (St Michael's College) for Connors 61 mins; Conor Hand (Navan RFC) for Doris, Martin Mulhall (Lansdowne FC) for Loughman, Tommy O'Brien (Blackrock College) for J O'Brien all 69 mins; Darragh Sweeney (Malahide RFC) for Rock, Óisín Dowling (St Michael's College) for Regan both 75 mins.
MUNSTER: Colm Hogan (Dublin University, Capt); Lee Molloy (Lansdowne), Calvin Nash (Young Munster), Paedar Collins (Garryowen), Liam Coombes (Young Munster); Alan Tynan (Young Munster), James Lennon (Exiles); Joey Conway (Castletroy College), Adam Moloney (St Munchin's College), Rory Burke (Cork Constitution), Fineen Wycherley (Young Munster), Sean O'Connor (Garryowen), Gavin Coombes (Young Munster), Alan Fitzgerald (Shannon), John Foley (Shannon).
Replacements: Jack Stafford (Shannon) for Foley 31 mins; Vince O'Brien (Cork Constitution) for Moloney 42 mins; Peter Kelleher (Cork Constitution) for Conway, Conor Fitzgerald (Shannon) for Tynan, Alex McHenry (Cork Constitution) for Collins all 53 mins; Bailey Faloon (Garryowen) for Lennon 62 mins; Liam O'Connor (Cork Constitution) for G Coombes 71 mins; Cameron Gray (Exiles) for Wycherley 76 mins.
Referee: Joy Neville (IRFU)