Jorge Grant netted his third goal in four matches as County, now unbeaten in five matches, moved eight points clear of danger.
Grant scored the winner in the 21st minute after a defensive mix-up caused by an under-hit Yann Songo'o back pass, with Jonathan Forte's initial effort initially blocked and in-form Grant first to react.
In first half stoppage-time on-loan Forest striker Grant should have claimed his second of the game but fired wide from 10 yards after his first strike was bravely blocked by right-back Oscar Threlkeld.
Plymouth striker Ryan Taylor's spectacular volley at the start of the second half had to be tipped over by goalkeeper Adam Collin.
In the 65th minute County substitute Jon Stead headed wide from Marc Bola's deep cross into the six-yard box.
Argyle almost secured a point but substitute Jordan Slew volleyed over 10 minutes from time after Collin's poor punch landed at his feet.
Match report supplied by the Press Association.
Match ends, Plymouth Argyle 0, Notts County 1.
Second Half ends, Plymouth Argyle 0, Notts County 1.
Foul by Sonny Bradley (Plymouth Argyle).
Jon Stead (Notts County) wins a free kick in the attacking half.
Jordan Slew (Plymouth Argyle) wins a free kick in the defensive half.
Foul by Curtis Thompson (Notts County).
Attempt missed. Michael O'Connor (Notts County) right footed shot from outside the box is too high.
Robert Milsom (Notts County) is shown the yellow card.
Corner,  Notts County. Conceded by Antoni Sarcevic.
Foul by James Spencer (Plymouth Argyle).
Elliott Hewitt (Notts County) wins a free kick in the attacking half.
Attempt saved. Robert Milsom (Notts County) left footed shot from outside the box is saved in the bottom right corner.
Jordan Slew (Plymouth Argyle) is shown the yellow card.
Yann Songo'o (Plymouth Argyle) wins a free kick in the attacking half.
Foul by Curtis Thompson (Notts County).
Foul by Yann Songo'o (Plymouth Argyle).
Jon Stead (Notts County) wins a free kick in the attacking half.
Corner,  Notts County. Conceded by Luke McCormick.
Attempt blocked. Jon Stead (Notts County) right footed shot from a difficult angle on the right is blocked.
Attempt missed. Jordan Slew (Plymouth Argyle) right footed shot from the left side of the box is just a bit too high.
Antoni Sarcevic (Plymouth Argyle) wins a free kick in the defensive half.
Foul by Jorge Grant (Notts County).
Yann Songo'o (Plymouth Argyle) wins a free kick on the right wing.
Foul by Jorge Grant (Notts County).
Yann Songo'o (Plymouth Argyle) wins a free kick in the attacking half.
Foul by Jon Stead (Notts County).
Substitution, Notts County. Curtis Thompson replaces Jonathan Forte.
Attempt saved. Jordan Slew (Plymouth Argyle) left footed shot from the left side of the box is saved in the centre of the goal.
Substitution, Plymouth Argyle. Jordan Slew replaces Matthew Kennedy.
Foul by Ryan Taylor (Plymouth Argyle).
Haydn Hollis (Notts County) wins a free kick in the attacking half.
Attempt missed. Yann Songo'o (Plymouth Argyle) header from the centre of the box misses to the left.
Corner,  Plymouth Argyle. Conceded by Marc Bola.
Foul by James Spencer (Plymouth Argyle).
Haydn Hollis (Notts County) wins a free kick in the attacking half.
Sonny Bradley (Plymouth Argyle) wins a free kick in the attacking half.
Foul by Shola Ameobi (Notts County).
Michael O'Connor (Notts County) is shown the yellow card.
Sonny Bradley (Plymouth Argyle) is shown the yellow card.
Substitution, Plymouth Argyle. Jake Jervis replaces Jakub Sokolik.
Notts County upset second-placed Plymouth at Home Park to edge further away from the League Two relegation zone.