Donegal put in a magnificent controlled display to despatch a poor Cavan side in Kingspan Breffni Park.
It was a brilliant display from Donegal with Eoin McHugh and Ciaran Thompson having standout games. Cavan were hugely disappointing, finishing with 13 men and they will do well to stay in the top flight after this display.
For Donegal, this win almost guarantees their top flight status after just four games.
Donegal completely dominated the opening half but only had a two point lead at the break. That was thanks, in a big way, to referee Conor Lane, who awarded three very soft frees to the Cavan men, when they were 0-5 to no score in arrears.
Donegal looked very sharp in the opening quarter and had five points on the board inside 13 minutes.
Michael Murphy had the first two points from frees, after fouls on Ryan McHugh and Frank McGlynn.
Ciaran Thompson then launched a mighty score from 48m and Eoin McHugh and Frank McGlynn kept the scoreboard ticking.
Michael Murphy also missed a free in this period while a Jason McGee effort was saved from going over the bar by a great leap by Cavan 'keeper Raymond Galligan.
There were 22 minutes on the clock when referee Conor Lane adjudged a foul on Sean Johnston as he ran alongside Paddy McGrath. Johnston pointed the gift free.
Donegal responded with Michael Murphy setting up Ryan McHugh for a sixth point. In the final ten minutes Cavan got two points in quick succession, another soft free against Neil McGee on Michael Argue which Johnston pointed. Almost immediately Conor Madden had Cavan's only point from play in the opening half.
All hell broke loose in the 31st minute as Killian Clarke cleaned Eoghan Ban Gallagher as he was driving forward along the sideline. A melee broke out and when it settled Conor Lane showed Cavan captain Killian Clarke a straight red card.
Cavan should have been reduced to 13 a minute later as Dara McVeety cleaned Ryan McHugh after he passed the ball. Conor Lane stopped play and called McVeety but then realised that he had booked him in the eight minute and he let him off with a warning. It was a black card offence and should have been punished.
To compound matters he awarded Cavan another soft free on the stroke of half-time which Gearoid McKiernan pointed to leave it 0-6 to 0-4 at the break.
Donegal got the perfect start to the second half with a point from Hugh McFadden and then Eoin McHugh hit a cracking goal after good approach work from Jason McGee and Jamie Brennan.
Seanie Johnston and Gearoid McKiernan pulled points back for Cavan before Jamie Brennan had a good Donegal point.
Ciaran Brady had a good Cavan point but Cian Mackey, who replaced Sean Johnston, missed an easy free. At the other end Ciaran Thompson found the range from a free on 53 minutes, but Cavan still remained dangerous with Niall Clerkin hitting the sidenetting.
Donegal kept the scoreboard ticking with Jamie Brennan and an exquisite effort from Ciaran Thompson. Indeed Thompson repeated the effort for his fourth while Michael Murphy added a free before the 62nd minute.
It got worse for Cavan as Cian Mackey was black carded and they had already used their six subs.
Ciaran Thompson almost had a goal as he blasted his fifth point just over the crossbar with Cavan in disarray
Scorers - Cavan: Sean Johnston 0-3,3f; Gearoid McKiernan 0-3,2f: Dara McVeety and Conor Madden0-2 each; Ciaran Brady 0-1.
Donegal: Ciaran Thompson 0-5,1f; Eoin McHugh 1-1; Michael Murphy 0-3,3f; Jamie Brennan 0-3; Frank McGlynn, Hugh McFadden, Ryan McHugh, Mark McHugh 0-1 each.
Cavan: Raymond Galligan; Fergal Reilly, Padraig Faulkner, Killian Brady; Martin Reilly, Ciaran Brady, Gerard Smith; Killian Clarke, Tomas Corr; Michael Argue, Dara McVeety, Conor Madden; Niall Clerkin, Gearoid McKiernan, Sean Johnston. Subs., Rory Dunne for Corr 14; Stephen Murray for K Brady; Niall Murray for Argue, both ht; Cian Mackey for Johnston 44; Joe Dillon for F Reilly 56; John McCutcheon for C Brady 58
DONEGAL: Mark Anthony McGinley; Paddy McGrath, Neil McGee, Eoghan Ban Gallagher; Caolan Ward, Frank McGlynn, Eoin McHugh; Jason McGee, Ciaran Thompson; Michael Carroll, Martin O'Reilly, Ryan McHugh; Hugh McFadden, Michael Murphy, Darach O'Connor. Subs., Jamie Brennan for O'Connor ht; Daniel McLaughlin for Carroll 47; Michael Langan for J McGee 49; Eamonn Doherty for Hugh McFadden 55; Mark McHugh for E McHugh 65; Paul Brennan for E Ban Gallagher 66
REFEREE: Conor Lane (Cork)