Jim Gavin’s side were at their ease throughout at the St Brigid’s club grounds in Blanchardstown and were assured of victory by half-time when they led by 17 points.
Gavin took the opportunity at that stage to make five changes and though the quality dipped in the second half — they outscored the Students by just two points in that period — he was happy to assess more fringe talent.
The lack of a real challenge from visiting IT Carlow made it difficult to judge how well Dublin’s players actually performed.
In truth, many looked like world beaters with Mick Deegan, Shane Carthy, and home favourite Paddy Andrews cutting the defence open with some sumptuous passes.
Costello was the player at the point of the sharpened attack and after finishing off a fine move for his first goal after 24 minutes then converted a second-half penalty.
All eyes were on Dublin’s full-back line following the news that All-Star Rory O’Carroll will spend this year travelling and working in New Zealand.
Jarlath Curley, full-back for St Vincent’s when they won the AIB All-Ireland club title, started in front of club mate and Dubs ‘keeper Michael Savage.
He performed well until being taken off at half-time with the goal that Dublin did concede being an unfortunate one. Savage thought he had done enough to keep Mark Sherry’s 15th minute shot out though the ball had apparently crossed the line before being cleared.
Aside from that, Dublin leaked just two points before Curley was one of the five players that made way at the break in a major reshuffle.
The tie was played on the Russell Park artificial surface and though the rain drove down all evening, Dublin’s passing was quick and crisp.
They had to fight back from a slow start against Wexford last weekend in Round 1, eventually earning a draw.
But there was never any danger of a repeat with Dublin leading by 1-11 to 1-0 until IT Carlow scored their first point in the 22nd minute.
Dublin will wrap up their Group A campaign on Sunday when they play DCU at a venue yet to be confirmed.
They will fancy themselves to progress to the last four on Sunday week and secure at least a semi-final tie before the Allianz League begins on January 30 against Kerry.
Those who will hope to earn a panel place throughout spring include Oisin Manning of St Jude’s who joined Curley and Eoin Culligan in the full-back line.
Niall Scully started at wing-back while Ciaran Reddin and Tomas Brady formed a new look midfield. Up front, Costello, who is bidding to regain his first team position, appears hell bent on forcing his way back in.
He kicked scores comfortably off both feet and was brilliantly assisted in attack by Andrews. St Brigid’s club man Andrews tore through the students during the first half and claimed 1-3 before going off at the break.
His 26th minute goal was a cracker as he delicately lobbed the keeper from the right of goals. Brady closed out the first-half scoring and Dublin led 2-16 to 1-2.
Much of their momentum appeared to be sapped by all the half-time changes. Deegan and Costello were best after the break with Deegan, who plays his club football in Meath, taking his tally to five points for the evening.
Jonny Cooper returned to action as a sub for Reddin too. IT Carlow improved and a well-worked goal from Chris Healy, who scored 1-2 in the second half, and 1-3 overall didn’t flatter them.
C Costello (2-6, 1-0p, 0-3f), P Andrews (1-3), M Deegan (0-5), T Brady, J Whelan, S Carthy, C McGuire (0-2 each), N Scully, P McMahon (0-1 each).
C Healy (1-3), M Sherry (1-0), C Conroy (0-2f) and K Ryan (0-2 each), N Kane (0-1).
M Savage; E Culligan, J Curley, O Manning; N Scully, P McMahon, J Small; C Reddin, T Brady; J Whelan, M Deegan, S Carthy; C Costello, P Andrews, C McGuire.
J McCarthy for Brady h/t, N Walsh for Carthy h/t, A Caffrey for Andrews h/t, M Concarr for Small h/t, G Hannigan for Curley h/t, J Cooper for Reddin 45.
R Sansom; I Ilunga, T Featherston, T O’Connell; A Dever, D Dunne, D Smyth; W Young, M Russell; C Conroy, K Ryan, E Buggie; C Healy, M Sherry, M Hurley.
J Mitchell for Dunne h/t, N Kane (0-1) for O’Connell h/t, S McGraynor for W Young 53, D Aston for Russell 66, A O’Brien for M Hurley 69.
N Hand (Louth).