It was no more than the battling Bees deserved for a spirited second-half display, despite going into the match without nine senior players through injury or suspension.
It was a poor, scrappy match on a bumpy pitch and six balls were kicked out of the ground in the first half-hour.
Former Gillingham team-mates Paul Smith and Andy Hessenthaler lined up opposite each other in midfield.
And it was Smith who was happiest at half-time after Torquay took the lead in the 45th minute.
Lee Mansell floated a free-kick from the right and veteran defender Craig Taylor scored with a far-post header.
But instead of pushing on for what would have been a crucial victory in their fight to avoid relegation, Torquay faded in the second half.
Barnet missed a great chance to equalise on the hour with Barry Cogan blasting over from 12 yards from a Richard Graham cross.
Bees boss Paul Fairclough made a triple substitution in the 72nd minute and it worked.
He sent on Oliver Allen for Adam Gross, Magno Vieira for Paul Warhurst and Nicolau for Graham.
In the last ten minutes debutant Stuart Lewis, on loan from Spurs, had a goalbound shot deflected behind, Vieira had a volley held by Torquay's 37-year-old goalie Kevin Miller and finally Nicolau scored.
Vieira started on the left, wriggled his way across the penalty area, slipped the ball to Nicolau and he forced it home at the far post.
The only blot on Barnet's gutsy display was three bookings for Gross, Simon King and Hessenthaler.
But it was Hessenthaler, not Smith, who was still smiling at the final whistle.
Torquay have now won only once in 22 games and are still five points adrift at the bottom of League Two.