Stevie Crawford's first goal since his summer move from Dunfermline ensured Argyle remain the Championship's surprise package with a third successive victory.
Crawford, the first ever Plymouth player to represent Scotland, struck a classy goal four minutes before the interval to give Argyle a two-goal cushion following captain Paul Wotton's opportunist strike in the second minute.
Wotton fired home a free-kick that caught Sunderland goalkeeper Thomas Myrhe unawares, before Crawford netted the all-important second, latching on to Micky Evans' flick-on to outpace the Sunderland defence and angle the ball home.
Sunderland raised their game after the interval and reduced the arrears with a Marcus Stewart goal midway through the half, the first that last season's second division champions have conceded in the Championship.
They might have rescued a point in the last minute when Kevin Kyle headed over, but Argyle hung on to claim their biggest scalp of the campaign.
Argyle took precisely 100 seconds to take the lead with their first goal at Home Park this season.
It came from a free-kick on the left-hand side, awarded against Stephen Wright for a foul on Crawford. Wotton took the free-kick and, although Myrhe's concentration cannot have been helped by a long delay as Argyle players made several protests to referee Phil Crossley over Sunderland's petty shirt-pulling, he should have stopped the shot.
The powerful shot was straight at him but he failed to lay any part of his hand on it.
Argyle enjoyed comfortable control of the game, especially with Tony Capaldi, back from international duty for Northern Ireland in Switzerland, who was a constant menace to Liam Lawrence and Wright on the left.
The Black Cats had claims for a penalty turned down when Julio Arca cut in from his left and saw his cross blocked by Wotton's arm, but the Argyle skipper was given the benefit of the doubt.
Argyle's second goal was route one. Goalkeeper Luke McCormick's long kick-out was headed expertly by Evans into the path of Crawford, who had drifted into space behind the Sunderland back line. The Scot's instant control gave him the time he needed to look up and slot the ball across Myrhe.
Sunderland began the second half showing greater composure and came close to gaining a reward when Lawrence picked up a poorly defended free-kick at the far post and drilled a cross across the face the goal which John Oster was close to touching home.
Wotton had a powerful free-kick from a dangerous position beaten out by the defensive wall, before Lawrence was again the instigator of another opportunity, his cross this time being headed wide by Carl Robinson.
With 25 minutes left, Sunderland manager Mick McCarthy made all three of his substitutions. Mark Lynch replaced the injured Wright, Sean Thornton came on for Lawrence, whose attacking play could not compensate for defensive failings, and Stephen Elliott replaced Oster, who reacted to his substitution by taking the offered tracksuit top and flinging it to the ground.
The changes had their desired effect, with Thornton's corner being headed in at the near post by Stewart for the first goal conceded by the Pilgrims since the penultimate weekend of the previous season.
Argyle lived on their nerve-endings and the impressive Thornton swung in a corner from the right which Kyle met full on in the dying seconds.
McCormick could only watch as the ball flashed past him and over the crossbar.