Michael Murphy's made his 100th Donegal appearance as Rory Gallagher's side edged out Down 1-11 to 0-11 in the Dr McKenna Cup opener at Ballybofey.
Second-half substitute Murphy's late point helped an experimental Donegal side hold off a committed Down outfit.
Frank McGlynn's early goal contributed to Donegal's 1-3 to 0-4 half-time lead.
Ciaran Thompson's third point helped Donegal move five ahead but Down kept battling and Donegal needed late Murphy and McGlynn points to stay clear.
Donegal boss Rory Gallagher named five debutants Jack O'Brien, Eoghan Ban Gallagher, Ciaran Thompson, Stephen McBrearty and Michael Carroll while Cathal Doyle, Joe McDermott, Joe Murphy and Gareth Johnson made their first Down appearances as Eamonn Burns took charge of the Mourne County for the first time.
McGlynn lobbed in Donegal's goal in the opening minute after being found by Odhran MacNiallais.
Peter Turley had an immediate chance to level from a Down goal chance but fired over the bar and two Thompson points helped Donegal lead by two at half-time with debutant Johnson and Aidan Carr among the Down first-half scorers.
Johnson added another Down point immediately after the restart but the visitors missed other scoring chances and Donegal increased their advantage to three with Martin O'Reilly, Hugh McFadden and man of the match Thompson all on target.
Donegal went close to notching a second goal as a fierce Jack O'Brien shot hit the underside of the crossbar with suggestions the ball may have bounced over the line before being cleared.
As Paddy McGrath hit what is believed to be his first ever inter-county point, Donegal appeared to be in command as they moved five clear but a Shane Dolan point started a Down revival as Donegal needed the late Murphy and McGlynn scores to keep the Mourne men at bay.
Murphy received a big cheer from the home crowd as he was introduced with 16 minutes remaining.
Bank of Ireland Dr McKenna Cup results
Derry 4-16 2-12 Antrim
Tyrone 3-17 0-11 Queen's
Donegal 1-11 0-11 Down
Fermanagh P-P St Mary's College
Armagh 0-11 2-08 Cavan
Monaghan 1-09 2-16 Ulster University