Leinster's young guns helped to maintain the province's winning streak as they recorded a 42-24 bonus-point win over Cardiff.
Twelve of the match-day squad for the BTK URC leaders had 18 or fewer Leinster appearances under their belt but that dozen did include South Africa's RG Snyman and France's Rabah Slimani.
The hosts didn't have it all their own way but had enough class in reserve to see off a Cardiff side who hadn't won in Ireland since 2017.
Tries from John McKee, Jack Boyle, Max Deegan, Luke McGrath, Charlie Tector and Rob Russell, and six conversions from Ross Byrne, earned Leo Cullen's side an 18-point victory in front of 17,951 on a perfect day for rugby in the Dublin 4 venue.
The win put Leinster onto 57 points after 12 rounds, well on course for a home knock-out run in the play-offs.
Cardiff, under interim coach Gethin Jenkins with Matt Sherratt overseeing Wales' Six Nations campaign, took a bonus point and remain in the top-eight.
While Leinster were without most of their frontline internationals, they were still able to include senior players Jimmy O'Brien, Byrne, McGrath, Will Connors and Deegan, while Boyle, who made his Test debut last weekend against Wales, started at loosehead.
Cardiff would have taken most encouragement out of the opening exchanges, thwarting Leinster with a jackal penalty when the hosts looked like capitalising on nine phases inside the 22.
Leinster flashed the ball out the line but the visitors put in their first-time tackles and more than held their own, with a couple of handling errors from Cullen's side helping Cardiff's cause.
The opening score came in the 15th minute after Deegan claimed a five-metre lineout throw and McKee steered the maul over the line, with Byrne adding the extras.
Cardiff struck back quickly however, with out-half Callum Sheedy setting Cam Winnett free in midfield; from there the full-back spun out a perfect pass for Harri Millard, who won the race to the line.
While Leinster dominated territory and possession, their handling and kicking was below standard and more indiscipline paved the way for the Welsh side to take the lead.
The Leinster defence went offside 10 metres out but captain Liam Belcher declined the kick and Thomas Young powered over a few phases after they tapped the penalty, with Sheedy converting to put Cardiff 12-7 up in the 31st minute.
Locks Diarmuid Mangan and Brian Deeny were carrying hard and McKee (above) looked certain to add a second but got held up over the line by Millard before Connors lost the ball as he attempted a pass close to the line.
Rey Lee-Lo broke away and Tommy O'Brien had to scramble to stop Millard going the length.
But there was a sting in the tail of the first half for the hosts with Boyle scoring Leinster's second.
Tector took a long lineout throw and broke the Cardiff line; Deegan and Byrne combined to put Jimmy O'Brien into space and McGrath quickly fed the ball to the latest Ireland international, who powered over in the corner.
Byrne converted to give Leinster a two-point lead at the break.
Cullen sent on Snyman (above) at the start of the second half to try and bring some more order to proceedings and Leinster had their third less than three minutes in.
Jimmy O'Brien and Hugh Cooney, lively throughout, brought play up the five-metre line and replacement Alex Mann was sin-binned as he conceded a penalty in the scramble back.
Deegan, who captained Ireland A last weekend, powered over after Leinster took a tap penalty with Byrne converting.
McGrath sniped over for Leinster's bonus-point try following another five-metre lineout as Leinster's quality began to show.
Leinster secure their fourth try and with it a bonus point as they start to put some real daylight between themselves and Cardiff.
— RTÉ Sport (@RTEsport) March 1, 2025
Watch Leinster v Cardiff live on RTÉ2 and https://t.co/bCe53VfDsj#RTEsport pic.twitter.com/00dgRyscee
Less than two minutes later, after Andrew Osborne's catch had led to a Leinster penalty, they had a fifth.
The same man came off his wing to take a pop pass from Byrne and fed Tector on the 22; the centre, named player of the match, had work to do and players to beat but powered his way over, with the out-half's conversion pushing the lead out to 35-12.
Cardiff appeared to be in for a long 25 minutes of rugby but they had the next say with Tommy O'Brien preventing a certain try for Millard in the corner off the restart but the wing wasn't to be denied from the next attack, the visitors' best passage of play.
After keeping the ball alive across the 22, Willett dinked a kick in behind and Millard plucked the ball out of the air before dotting down.
Leinster handed debuts to prop Ivan Soroka, on the for the excellent Boyle, and scrum-half Oliver Coffey as numerous replacements stymied the momentum.
The lively Gabriel Hamer-Webb beat his man on the outside before passing inside to Ellis Bevan, who ran in for the try bonus.
Full-time - Leinster 42-24 Cardiff: Rob Russell makes a welcome return from injury to round off the scoring for Leinster who claim an 18-point win. #RTEsport pic.twitter.com/PH7axb8bj2
— RTÉ Sport (@RTEsport) March 1, 2025
But Leinster had the last say with Russell, on his return from injury, diving over in the corner with the try being awarded following a lengthy TMO consultation.
SCORERS
Leinster - Tries: McKee, Boyle, Deegan, McGrath, Tector, Russell
Cons: Byrne (6)
Cardiff - Tries: Millard (2), Young, Bevan
Cons: Sheedy, De Beer
Leinster: Jimmy O'Brien; Tommy O'Brien, Hugh Cooney, Charlie Tector, Andrew Osborne; Ross Byrne, Luke McGrath (capt); Jack Boyle, John McKee, Rabah Slimani; Diarmuid Mangan, Brien Deeny; Alex Soroka, Will Connors, Max Deegan
Replacements: Stephen Smyth (for McKee 57), Ivan Soroka (for Boyle 68), Rory McGuire (Slimani 68), RG Snyman (Mangan h/t), Scott Penny (Connors 62), Oliver Coffey (McGrath 68), Liam Turner (Cooney 77), Rob Russell (T O'Brien 60).
Cardiff: Cam Winnett; Gabriel Hamer-Webb, Rey Lee-Lo, Rory Jennings, Harri Millard; Callum Sheedy, Johan Mulder; Danny Southworth, Liam Belcher (capt), Rhys Litterick; Josh McNally, Rory Thornton; Ben Donnell, Thomas Young, Alun Lawrence
Replacements: Efan Daniel (for Belcher 64), Rhys Barratt (Southworth 52), Will Davies-King (Litterick 52), Seb Davies (Donnell 62), Alex Mann (McNally 32 HIA), Ellis Bevan (Mulder 62), Tinus de Beer (Sheedy 69), Regan Grace (Millard 62).
Referee: Andrea Piardi (FIR)
