The Scotstown attacker, who helped his club to the AIB Ulster Club final late last year, was unstoppable and dovetailed superbly with powerful full-forward McGraynor.
Man-mountain McGraynor gave Athlone IT huge problems and had a hand in DCU’s first three goals, setting up Carey for two of them and finishing one off himself.
DCU took their time to get going and were just four points up entering injury-time before two goals, from Carey and McGraynor, gave them a comfortable advantage.
They simply scored at will after that and with an arsenal of inter-county talent at their disposal, they are rightfully favourites to retain the title.
Longford’s Michael Quinn, a former Australian Rules player, was superb around the middle third while Dublin duo Shane Carthy and Davy Byrne got through plenty of good work.
In attack, Mayo’s Diarmuid O’Connor came into his own in the second-half and finished with 1-1, the same tally as rising Roscommon star and county medallist Ultan Harney.
To put DCU’s strength in depth in perspective, they didn’t even require another ex-Australian Rules player, Colm Begley, Tipperary midfielder Steven O’Brien, or Dublin’s 2014 All- Ireland U21 final hero Conor McHugh.
DCU manager Niall Moyna has an equally impressive back room team with Meath legend Sean Boylan continuing his role as right hand man.
The Glasnevin outfit’s reward for the 22-point drubbing is a quarter-final tie against IT Carlow who surprisingly overcome IT Sligo earlier in the day.
DCU will want to start better in that tie as they didn’t put real daylight between themselves and Athlone IT until those two first-half injury-time goals. With half an hour gone, they led 0-6 to 0-2 and were finding Kieran Martin, the Westmeath star who destroyed Meath in last year’s Leinster championship, difficult to handle.
All of Athlone’s attacking play came through Martin and he scored both their first-half points and 1-5 of their overall tally.
Carey’s first goal was significant though and appeared to open the floodgates for DCU. McGraynor fetched superbly and though the ball spilled loose, Carey was on hand to apply a routine finish from close range.
McGraynor then netted himself and once again did brilliantly to get his hands to Quinn’s diagonal ball in before holding off his man and firing a low finish to the net. DCU led 2-6 to 0-2 at half-time and stretched the margin to nine points early in the second-half when Carey netted again.
The provider was McGraynor, unsurprisingly, and he played a neat one-two with Carey before the Ulster man slotted beyond Darren O’Connell.
Martin pulled back a goal for Athlone IT in the 44th minute after great work by substitute Killian Rudden who drew a fine save from the DCU ‘keeper with his very first kick. Martin gobbled up the rebound and the midlanders had some hope of a potential fight-back.
But the revival was quickly stamped out as DCU went up the other end from the resulting kick-out and netted their fourth goal through Carthy. Carey rounded off his hat-trick in the 47th minute but the best goal of the lot came from O’Connor in the 62nd minute.
Substitute David Mannix from Kerry played O’Connor in but he still had plenty to do before a brilliant shot across goals from right to left.
Mannix did well overall and kicked two points to put forward his own claim to a starting spot next time out.
S Carey (3-6, 3 frees), U Harney (1-1), C McGraynor and S Carthy (1-0 each), D Mannix, D O’Connor and M Quinn (0-2 each), Dessie Ward (0-1).
K Martin (1-5, 3 frees), C McMonagle (0-2)
B Flynn, J Smith, D Ward, P McKenna; D Byrne, C Moynagh, S Attride; S Carthy, C McGonagle; M Quinn, D O’Connor, M Plunkett; C McNally, C McGraynor, S Carey.
E Smith for Ward (h/t), R Lyons for Plunkett (h/t), U Harney for McNally (43), C Breheny for Quinn (50), R Connor for McKenna (50), D Mannix for McGraynor (54).
D O’Connell; D Monagle, A Claffey, M Kearney; D Wharton, S Flynn, A Byrne; E Quigley, M Daly; D McDermott, K Martin, A Fitzpatrick; C McMonagle, T Watts, A Coffey.
D Petit for Coffy (36), K Rudden for Daly (43).
F Kelly (Longford).