Avenging a first round defeat in Cork, Charlie Doel's Leinster team overcame Munster 28-14 in a very entertaining Interpro final played at Shay Murtagh Park.
Tullamore centre Sophie McDonagh's first-half brace of tries built crucial momentum, while captain Emily Miller and Síofra McGlynn also crossed the whitewash for the victorious Blues.
Seeking their first Championship title since 2022, Munster gave it their all, and Damien Hicks' charges - driven on by Eden Waters and a workhorse pack - were only 21-14 behind at half-time.
Charlotte Deegan and Garryowen's Emer Purtill, with her fourth try of the competition, both touched down, but the influential Sophia White converted prop McGlynn's late second-half effort to see Leinster retain the trophy.
Meanwhile, Connacht won the opening match of an exciting finals day, as Losalia Atonio helped herself to two tries in a 33-15 play-off triumph over Ulster.
In Claire Coghlan's first season in charge, Connacht had an impressive return of three wins in four games as they convincingly claimed a third place finish.
It was not the result that Dan Carson's Ulster outfit craved, but compared to their 67-5 defeat to Connacht in round 1, this afternoon's losing margin showed how much they have improved from week to week.
The westerners' front row was on fire during the opening 35 minutes, with Tuam/Oughterard hooker Atonio touching down twice, and Cairínn Kearns and Amy Moran also contributing tries.
Centre Mila Fralkova broke free for Connacht's fifth try, while her Buccaneers club-mate Sally Fleming tallied up eight points from the tee. The second half finished seven points apiece, with Omagh's Emily Irwin claiming a converted score.
PWC UNDER-18 GIRLS INTERPROVINCIAL CHAMPIONSHIP FINAL:
LEINSTER U-18 GIRLS 28 MUNSTER U-18 GIRLS 14, Mullingar RFC
Scorers: Leinster: Tries: Sophie McDonagh 2, Emily Miller, Síofra McGlynn; Cons: Sophia White 4
Munster: Tries: Charlotte Deegan, Emer Purtill; Cons: Eden Waters 2
HT: Leinster 21 Munster 14
LEINSTER U-18 GIRLS: Caoimhe O'Mahony (Mullingar RFC); Lily Harney (Naas RFC), Saffron Adams (Portlaoise RFC), Sophie McDonagh (Tullamore RFC), Robyn O'Reilly (Tullamore RFC); Sophia White (Arklow RFC), Maebh Ní Cholla (Tullamore RFC); Síofra McGlynn (MU Barnhall RFC), Aimee Deering (Cill Dara RFC), Simi Shanu (De La Salle Palmerston FC), Molly Hurst (Edenderry RFC), Emma O'Rourke (Navan RFC), Lily Brophy (Portlaoise RFC), Milita Valteryte (Dundalk RFC), Emily Miller (Cill Dara RFC) (capt).
Replacements: Zoe Byrne (Arklow RFC), Lauren Shevlin (Dundalk RFC), Lucy Noons (Cill Dara RFC), Ruby Osumah (Tullamore RFC), Mila Mihajlovic (Portarlington RFC), Maggie Kerins (Navan RFC), Catherine Murphy (Athy RFC), Pearl Tyner (Arklow RFC).
MUNSTER U-18 GIRLS: Cate Foley (Kilrush RFC/Ennis RFC); Emer Purtill (Garryowen RFC), Alice O'Donovan (Bantry Bay RFC/Rebellettes), Ruby Wiley Murphy (Scariff RFC/Richmond RFC), Cora Miller (Waterpark RFC); Eden Waters (Richmond RFC/Scariff RFC), Grace Cronin (Bantry Bay RFC/Rebellettes); Alice Buckley (Ballincollig RFC), Richelle Kingston (Dunmanway RFC/Rebellettes), Charlotte Deegan (Fethard RFC), Sadhbh Brennan (Bantry Bay RFC/Rebellettes), Laura Danaher (Scariff RFC/Richmond RFC), Danielle Naughton (Abbeyfeale RFC/Killarney RFC), Caitríona Conroy Walsh (Dungarvan RFC), Julie Moynihan (Midleton RFC).
Replacements: Aobh Culloty (Tralee RFC), Róisín Cullinane (Midleton RFC), Julie Cunningham (Clonakilty RFC), Lisa O'Mahony (Ballincollig RFC), Sadhbh Whelan (Scariff RFC/Richmond RFC), Sarah Fennell (Tralee RFC), Saoirse Quinn (Ennis RFC), Sheila O'Donoghue (Kanturk RFC).
PWC UNDER-18 GIRLS INTERPROVINCIAL CHAMPIONSHIP 3RD-4TH PLACE PLAY-OFF:
CONNACHT U-18 GIRLS 33 ULSTER U-18 GIRLS 15, Mullingar RFC
Scorers: Connacht: Tries: Losalia Atonio 2, Cairínn Kearns, Amy Moran, Mila Fralkova; Cons: Sally Fleming 4
Ulster: Tries: Isabella Taylor, Emily Irwin; Con: Joy Lemon; Pen: Joy Lemon
HT: Connacht 26 Ulster 8
CONNACHT U-18 GIRLS: Niamh Gannon (Tuam RFC/Oughterard RFC); Leah McNamara (Westport RFC), Esther Albert (Ballinasloe RFC), Mila Fralkova (Buccaneers RFC), Elsie Yewlett (Sligo Rugby); Sally Fleming (Buccaneers RFC), Kitty Sweeney (Westport RFC) (capt); Amy Moran (Loughrea RFC), Losalia Atonio (Tuam RFC/Oughterard RFC), Cairínn Kearns (Gort RFC/Monivea RFC), Méabh Grennan (Galway Corinthians RFC), Aoibhinn Lyons (Westport RFC), Cora Heneghan (Buccaneers RFC), Ruth Conway (Westport RFC), Isabella Garvey (Sligo Rugby).
Replacements: Millie Ager (Claremorris Colts RFC), Róise Ní Scanláin (Tuam RFC/Oughterard RFC), Holly Meehan (Gort RFC/Monivea RFC), Orla Palasz (Westport RFC), Rhea Sestak (Loughrea RFC), Gemma Eivers (Buccaneers RFC), Maebh Smith (Claremorris Colts RFC), Chloe O'Connor (Buccaneers RFC).
ULSTER U-18 GIRLS: Cora Hayes (Cooke RFC); Katelyn Magee (Banbridge RFC) (capt), Emily Irwin (Omagh Academicals RFC), Sophie Hamilton (Omagh Academicals RFC), Anna Murray (Ballymena RFC); Joy Lemon (Donaghadee RFC), Rachel Kelly (Malone RFC); Erin Playfair (Donaghadee RFC), Alanna Scullion (Cooke RFC), Aoife Kirkpatrick (Ballymena RFC), Dearbhla Smith (Virginia RFC), Jessica Long (Letterkenny RFC), Yoanna Natovska (Ballymoney RFC), Casey Johnston (Virginia RFC), Isabella Taylor (Ballymena RFC).
Replacements: Grace Fitzpatrick (Banbridge RFC, Isabella Copeland (Banbridge RFC), Charlotte Boyd (Clogher Valley RFC), Cara Cowan-Smyth (Ballymoney RFC), Olivia Beggs (Carrickfergus RFC), Rachel Douglas (Banbridge RFC), Charlotte Thompson (Ballymoney RFC), Zara Wright (Clogher Valley RFC).
