A late strike from Jason Price sealed Doncaster's berth in the Johnstone's Paint Trophy final at the expense of Crewe at the Keepmoat Stadium.
The teams were 3-3 on aggregate going into the second leg before Luke Varney slotted in and Ryan Lowe's close-range header gave Crewe a 5-3 advantage.
Paul Heffernan pulled one back with a turn-and-shot before converting a penalty after Price was fouled.
With a minute left, Price poked in from six yards for the last-gasp winner.
Doncaster: Smith, Lockwood, Stephen Roberts (Nelthorpe 76),
Lee, Gareth Roberts (Paul Green 43), O'Connor,
Stock (Thornton 70), Wilson, Coppinger, Heffernan, Price.
Subs Not Used: Richardson, Hird.
Booked: O'Connor, Price.
Goals: Heffernan 63, 83 pen, Price 89.
Crewe: Williams, Otsemobor, Jones, Baudet, Bignot,
Roberts (Higdon 90), Rix, O'Connor, Vaughan, Lowe (Maynard 76),
Varney.
Subs Not Used: Tomlinson, Cox, O'Donnell.
Booked: Baudet, Jones, O'Connor.
Goals: Varney 32, Lowe 36.
Agg (6-5)
Att: 12,561
Ref: T M Kettle (Rutland).