The Kingdom needed huge contributions from player of the match Sarah Houlihan and substitute Louise Ní Mhuircheartaigh to get over the line.
Ní Mhuircheartaigh didn’t start the game due to an injury but was sent in to rescue her colleagues late in normal time — and she did just that with two crucial points from play.
Both sides played an extremely defensive brand of football in the opening half and forwards on both sides found themselves heavily outnumbered.
But the lateral movement of Patrice Dennehy and Sarah Houlihan allowed Kerry to pick off six early scores in heavy traffic, to lead by three after 20 minutes.
A brave punched goal by Emma McCrory got Donegal right back into the tie, however, and a second goal from Geraldine McLaughlin gave them a 2-4 to 0-9 interval lead.
Neither side led by more than two points at any stage in the second half and as Donegal grew in confidence it looked as if an upset might be on the cards.
Katy Herron struck two wonderful long-range points to give them the lead on two separate occasions but Ní Mhuircheartaigh saved Kerry’s skin with a point just 20 seconds after being introduced, while Laura Rogers delivered the equaliser.
Kerry’s supremacy finally began to tell and a 1-3 salvo in just five minutes of play towards the end of the first period of extra-time essentially killed off Donegal’s challenge.
Louise Galvin scored the crucial goal after Ní Mhuircheartaigh picked open the Donegal defence and the beaten Munster finalists had some badly-needed breathing room.
Donegal reduced the gap with some late points but Kerry’s Cáit Lynch and Aisling Leonard ensured that they never came close to getting the third goal they needed.
Scorers for Kerry: S Houlihan 0-8 (4f), L Scanlon (1f), P Dennehy, B Breen 0-3 each, L Galvin 1-0, L Ní Mhuircheartaigh 0-2, E Sherwood, L Rogers, D Hallissey 0-1 each.
Scorers for Donegal: G McLaughlin 1-6 (0-4f), K Herron 0-4, E McCrory 1-0, SJ McDonald 0-2, Niamh McLaughlin, K Guthrie 0-1 each.
KERRY: E Murphy; A Lyons, A Desmond, D Hallissey; E Sherwood, C Kelly, D Corridan; L Scanlon, B Breen; M Quirke, C Lynch, A Leonard; P Dennehy, L Galvin, S Houlihan.
Subs: L Rogers for Corridan (46), M O’Connell for Scanlon (46), L Ní Mhuircheartaigh for Galvin (52), Galvin for Rogers (65), C Buckley for O’Connell (74).
DONEGAL: L Gallagher; Nicole McLaughlin, E Gallagher, O Carr; R Boyle, K Keaney, S McGroddy; K Herron, E Ward; Niamh McLaughlin, R McCafferty, K Guthrie; SJ McDonald, G McLaughlin, E McCrory.
Subs: K Feeney for McGroddy (31, temp), A Cunningham for McCafferty (45), Feeney for McGroddy (57), R Friel for McCrory (FT), C Hegarty for Boyle (63), J O’Donnell for Feeney (70), AM Logue for Friel (74), K Wilson for Nicole McLaughlin (78)
Referee: Des McEnery (Westmeath).