Title-chasing Argyle had stuttered of late with only one win in six games and failed to get a shot on target until their 69th-minute opener when Graham Carey floated a free-kick to the far post from the right-hand edge of the box and Sonny Bradley headed home at the far post.
The points were sealed shortly afterwards when Krystian Pearce was booked for a foul on Carey 25 yards from goal and the Plymouth man's free-kick was unstoppable into the top-left corner.
Somehow Mansfield had failed to score in a one-sided first half.
Inside the first three minutes Ben Whiteman curled wide of the far post and Alex MacDonald forced Luke McCormick to save at his near post after Argyle were caught out by a quickly-taken free-kick.
Matt Green was just unable to lift the ball high enough to beat the keeper after reaching Gary Sawyer's short back header after nine minutes.
MacDonald wasted two more chances, firing over after great work by Matt Green and tamely volleying at the keeper while Rhys Bennett headed a corner straight at McCormick.
Argyle's lone first-half chance came when Carey curled a 20-yard free-kick just wide after 18 minutes.
Match report supplied by the Press Association.
Match ends, Mansfield Town 0, Plymouth Argyle 2.
Second Half ends, Mansfield Town 0, Plymouth Argyle 2.
Attempt missed. Danny Rose (Mansfield Town) header from the left side of the six yard box is just a bit too high following a corner.
Corner,  Mansfield Town. Conceded by Yann Songo'o.
Attempt missed. Danny Rose (Mansfield Town) header from the left side of the box is close, but misses the top right corner following a corner.
Corner,  Mansfield Town. Conceded by Ryan Donaldson.
Attempt blocked. Shaquile Coulthirst (Mansfield Town) right footed shot from the centre of the box is blocked.
Foul by Malvind Benning (Mansfield Town).
Jake Jervis (Plymouth Argyle) wins a free kick on the right wing.
Substitution, Plymouth Argyle. Gary Miller replaces David Fox.
Substitution, Mansfield Town. Alfie Potter replaces Alexander MacDonald.
Attempt saved. Shaquile Coulthirst (Mansfield Town) with an attempt from the right side of the six yard box is saved in the centre of the goal.
Attempt missed. Danny Rose (Mansfield Town) header from the left side of the six yard box is close, but misses to the left following a set piece situation.
Hayden White (Mansfield Town) wins a free kick on the right wing.
Ryan Donaldson (Plymouth Argyle) is shown the yellow card for a bad foul.
Foul by Ryan Donaldson (Plymouth Argyle).
Attempt blocked. Malvind Benning (Mansfield Town) left footed shot from the left side of the box is blocked.
Foul by Shaquile Coulthirst (Mansfield Town).
Ryan Donaldson (Plymouth Argyle) wins a free kick in the attacking half.
Substitution, Mansfield Town. Danny Rose replaces Matt Green.
Substitution, Mansfield Town. Shaquile Coulthirst replaces Lee Collins.
Goal!  Mansfield Town 0, Plymouth Argyle 2. Graham Carey (Plymouth Argyle) from a free kick with a left footed shot to the top left corner.
Krystian Pearce (Mansfield Town) is shown the yellow card for a bad foul.
Foul by Krystian Pearce (Mansfield Town).
Graham Carey (Plymouth Argyle) wins a free kick in the defensive half.
Foul by Matt Green (Mansfield Town).
Oscar Threlkeld (Plymouth Argyle) wins a free kick in the defensive half.
Goal!  Mansfield Town 0, Plymouth Argyle 1. Sonny Bradley (Plymouth Argyle) header from very close range to the top left corner. Assisted by Graham Carey with a cross following a set piece situation.
Foul by CJ Hamilton (Mansfield Town).
Graham Carey (Plymouth Argyle) wins a free kick on the right wing.
Foul by Rhys Bennett (Mansfield Town).
Jake Jervis (Plymouth Argyle) wins a free kick in the defensive half.
Attempt missed. Benjamin Whiteman (Mansfield Town) right footed shot from outside the box is too high from a direct free kick.
Krystian Pearce (Mansfield Town) wins a free kick in the attacking half.
Foul by Yann Songo'o (Plymouth Argyle).
Substitution, Plymouth Argyle. Jake Jervis replaces Jordan Slew.
Hayden White (Mansfield Town) wins a free kick on the left wing.
Foul by Jordan Slew (Plymouth Argyle).
Attempt saved. Alexander MacDonald (Mansfield Town) right footed shot from a difficult angle and long range on the right is saved in the bottom right corner.
Foul by Matt Green (Mansfield Town).
Two goals in five second-half minutes saw Plymouth earn victory after being given a searching examination by play-off chasing Mansfield.