Last year's beaten finalists Donegal took time to settle in Birmingham, before running out comfortable winners.
A ninth-minute goal from Kevin Codd put Warwickshire ahead, but points from Niall Campbell and Enda McDermott reeled them in. McDermott then scored the first of his two goals, leaving Donegal 1-7 to 1-5 up at the break.
The Ulster men took control on the resumption with a Stephen Boyle point followed by a goal from Eugene Organ and two more points from Campbell.
Warwickshire were rocked but had begun to compose themselves -- with Codd leading the fightback from frees -- when Seamus Carey was sent off for a second bookable offence.
There was no way back for the hosts from that point as Donegal scored at will.
Man of the Match -- Niall Campbell (Donegal)
Scorers -- Donegal: E McDermott 2-3, N Campell 0-8, E Organ 1-2, J Donnelly, P Sheridan, S Boyle 0-1 each. Warwickshire: K Codd 1-7, J Bergin, D Kelly 0-2 each, S Carey, K Boxwell 0-1 each.
Donegal -- P O'Brien7; S O'Connor 6, C Breathnach 5, A McDermott 5; J Donnelly 6, C Dowds 5, J Boyle 5; P Sheridan 7, S Boyle 7; S McVeigh7, E Organ 8, C Mathewson 6; M McGee 5, E McDermott 8, N Campell 9. Subs: P Burns 5, R McDermott 6.
Warwickshire -- L Boxwell 6; P Breen 5, E Hansbery 4, C Vaughan 6; C Brough 5, ECahill 4, D Neylon4; K Codd 8, S O'Hanlon 5; J Bergin 6, S Carey 5, C Maskey 5; D Kelly7, K Boxwell 7, P Creehan 6. Subs: J O'Dwyer 5, B Mannion 5.
Ref -- D Hughes (Carlow).