DCU were actually level with just 14 minutes to go, despite being down to 14 men since early in the game.
However, eight CIT points without reply in the run-in sealed victory for the hot favourites and tournament hopefuls.
Mulcahy suggested full-forward Conor Hammersley was the best player on show.
He agreed, though, that O’Dwyer’s scores were crucial and the man who famously missed a free to win last year’s drawn All-Ireland final appears in strong form approaching the Allianz League.
“John will always stand up for you when you need him to, always,” said Mulcahy. “He enjoys the big games. He seems to grow a little bit on big days, whereas others might shrink into themselves. John has that little bit of personality to step up. He actually had a slight injury coming in, but he came up trumps for us.”
Mulcahy said CIT have big ambitions in the competition, having reached two of the last three finals.
However, they found it difficult for three quarters of this game, as DCU battled gamely, despite losing centre-back Pat Carroll to a third minute dismissal. He was shown a straight red card by experienced referee Brian Gavin for an apparent strike.
CIT took full advantage by moving 0-4 to 0-1 clear after 11 minutes, despite playing into a strong and biting breeze.
Stubborn DCU were, however, back level by the 24th minute, when Galway’s Padraig Brehony pointed to make it 0-5 apiece. When Dubliner Kevin O’Flynn stroked home a goal from a tight angle close to the right end line, DCU took a surprise lead.
A Hammersley point levelled it at half-time, 1-5 to 0-8, and they were still tied with just 14 minutes remaining after Brehony’s second point.
However, Cork’s Mark Ellis had an immediate impact with a great point to begin a CIT scoring spree. Having found scores difficult to come by — CIT had a 14-minute barren stretch early in the second-half — they suddenly opened up with their best play.
O’Dwyer converted one free from all of 90 metres, before firing over a beauty from the right wing. The Tipp man was also influential in creating scores for others and showed his combative side with several big hits.
CIT play St Pat’s-Mater Dei in Dublin next Thursday, then close their group campaign at home to UCD.
Scorers for CIT: J O’Dwyer (0-8, 0-7 frees), C Hammersley (0-3), D Lordan, J Cronin, M Ellis, B Cooper, J Cashman and J Herlihy (0-1 each).
Scorers for DCU: K O’Flynn (1-0), D Breathnach (0-3, two frees), P Brehony (0-2), D Staunton (0-1).
CIT: G Minihane (Courcey Rovers); S Murphy (Blackrock), A Dennehy (Charleville), T Lawrence (Brian Dillons); J Herlihy (Newtownshandrum), M Russell (Aghada), C Buckley (Na Piarsaigh); W Murphy (Meelin), A Walsh (Kanturk); D Lordan (Courcey Rovers), J Cronin (Lisgoold), B Cooper (Youghal); J O’Dwyer (Killenaule), C Hammersley (Clonoulty Rossmore), K Kavanagh (Carrigaline).
Subs: M Ellis (Millstreet) for Lorden (40), J Cashman (Lisgoold) for Russell (48), P White (Midleton) for Kavanagh (59).
DCU: C Ryan (Whitehall Colmcilles); P Gill (Burgess), R Lennon (Bennettsbridge), G Bennett (St Mullin’s); G Bailey (St Aidan Fern’s), P Carroll (Lisdowney), S Murphy (St James’); K Fitzgerald (Passage), T French (Adamstown); P Brehony (Tynagh/Abbey-Duniry), K O’Flynn (St Sylvester’s), M Daly (Lough Lene Gaels); D Breathnach (An Rinn), C Curran (Dungarvan), D Staunton (Glenealy).
Subs P Burke for Gill (30), E Smith for Curran (57), C Egan for O’Flynn (57).
Referee: B Gavin (Offaly).