Plymouth substitute Deane Smalley scored a last-gasp penalty as the Pilgrims claimed a 1-1 draw with first-time visitors Stevenage.
Referee Kevin Johnson added six minutes of added time and in the closing seconds Argyle were awarded a spot kick after Bira Dembele handled the ball during a goalmouth scramble.
Stevenage deservedly took a 54th minute lead through half-time substitute Connor Calcutt, who looped an inch-perfect header over home goalkeeper Luke McCormick for his first Boro goal.
Charlie Lee set the move in motion with a superb forward pass that was hooked on by Chris Whelpdale from the right and finished in style by Calcutt.
Plymouth boss John Sheridan responded with a triple substitution, sending on strikers Marvin Morgan and Smalley as well as attacking midfielder River Allen.
However it was Stevenage who came closest to scoring, again, as Simon Walton's corner was met by Dean Wells' downward bullet header straight into the clutches of keeper McCormick.
At the other end, Jason Banton's shot on the run from 20 yards was turned around the post by Sam Beasant as Plymouth finally threatened their visitors by forcing a string of corners.