Promotion to the top flight of the Allianz NHL remains a long shot but a big Parnell Park win has at least kept Dublin in the hunt, mathematically at least.
Division 1B defeats to Offaly and Waterford dented the Dubs' top-two hopes but they at least did the needful here, streaking past Carlow with nine points to spare.
Donal Burke led the scoring for Dublin, striking nine points to bring his overall league takings to 0-25 whilst goalscorers Brian Hayes and David Purcell were among 11 different scorers for the hosts on the evening.
Conor Burke also stood out with five points from play and midfield colleague Conor Donohoe added three, wrapping up the scoring with a sumptuous late point from a line ball.
Dublin manager Niall O Ceallachain will be satisfied with how his team worked the ball precisely through the lines, scoring virtually at will and consigning the visitors to their first defeat of the campaign.
Carlow arrived with their own promotion hopes following two draws and a landmark win over Waterford but led only briefly early on and chased Dublin for the majority.
They will play Laois in a refixtured tie next weekend while Dublin will wrap up their group campaign against the same opposition in Portlaoise on March 22.
Good news for Dublin, aside from the two points, was the seasonal return of former All-Star Danny Sutcliffe while Andrew Jamieson-Murphy played his first game for Dublin since 2023. There were also full debuts for ex-footballer Conor McHugh and goalscorer Purcell.
Dublin could easily have reached Round 6 with full points, instead of four from a possible eight, having been narrowly beaten by Offaly at Croke Park and then Waterford last weekend.
Cian O'Sullivan was red carded in the Deise defeat and his suspension opened the door for Purcell to make his first league start for the Dubs.
Purcell seized the chance, slotting into a full-forward line that contained Donal Burke and Diarmaid O'Dulaing and sniping an early 1-01.
Allianz Hurling League standings
Dublin were just starting to impose themselves after a relatively slow start when Purcell burst clear in the 21st minute for a terrific solo goal, firing across goal and beyond Brian Tracey.
It wasn't the game's first goal, that honour went to Carlow's Chris Nolan who punished an errant Dublin puck-out and returned the sliotar with interest to the Dublin net.
But after initially falling three points behind, Dublin soon regrouped and reeled off two separate bursts of four points in a row before the Purcell goal to lead 1-11 to 1-05.
McHugh also came into the Dublin team for Paddy Smyth, the former Dublin footballer and four-time All-Ireland SFC medallist making his small ball debut.
McHugh spent seven seasons up front with the Dublin footballers between 2015 and 2021, making 20 appearances, but has excelled more recently in defence with Leinster and All-Ireland club hurling champions Na Fianna.
Dublin continued to pile on the misery, pointing through Donal Burke, O Dulaing and Fergal Whitely before Brian Hayes sniped their second goal.
He dummied cleverly to make space at the clubhouse end but his shot was directly at Tracey who couldn't keep it out, allowing Dublin to soar 2-14 to 1-06 clear.
With 26 minutes on the clock, Dublin had opened up a dozen-point advantage and things already looked ominous.
Paddy Boland pulled back a goal for Carlow but they still had it all to do chasing a Dublin side 2-19 to 2-08 clear at half-time, with 10 different scorers.
Carlow reeled off five of the first six points in the second-half to ignite the contest before winning a 50th minute penalty when Boland pulled a long ball from the air and was fouled by Kevin Burke.
But Nolan's shot was expertly saved by Sean Brennan, leaving the gap at eight, 2-22 to 2-14.
It was a significant turning point because the miss sapped all of Carlow's momentum and sub Marty Kavanagh's late 1-01 was only consolation at that stage.
Dublin: Sean Brennan; John Bellew, Conor McHugh, David Lucey; Kevin Burke (0-01), Chris Crummey (0-01), Daire Gray (0-02); Conor Burke (0-05), Conor Donohoe (0-03, 0-01 s/l); Fergal Whitely (0-01), Brian Hayes (1-02), Ronan Hayes (0-03); Diarmaid O Dulaing (0-01), Donal Burke (0-09, 0-06f), David Purcell (1-01).
Subs: Sean Currie for David Purcell 41, Danny Sutcliffe for Ronan Hayes 53, Andrew Jamieson-Murphy for O Dulaing 53, Paddy Smyth for Lucey 53, Paul O'Dea for Crummey 66.
Carlow: Brian Tracey; Paul Doyle, Evan Kealy, Dion Wall; Jack McCullagh, Kevin McDonald (0-01, 0-01f), Niall Bolger; Ciaran Whelan (0-03, 0-03f), James Doyle (0-05, 0-03f); Jon Nolan (0-01), Ted Joyce (0-01), Eric English (0-01); Paddy Boland (1-00), Conor Kehoe (0-01), Chris Nolan (1-01).
Subs: Paidi O Shea for Bolger h/t, Fiachra Fitzpatrick for Whelan h/t, Donagh Murphy (0-01) for Kehoe h/t, Richard Coady (0-01) for English 53, Martin Kavanagh (1-01) for Joyce 58.
Referee: Colm McDonald (Antrim).
