John Sheridan praised his Plymouth side for their perseverance as they beat Northampton 1-0 at Home Park.
Victory lifts Sheridan's Argyle - unbeaten in three League Two games - up to 17th in the table following back-to-back 1-0 wins.
Sheridan said: "I am just really pleased for the players and full credit to them for showing the will to win, endeavour to really grind it out, get the result and go to the final minute to win the game. We've done that for the last two games now."
Sheridan's inspirational substitution was homegrown playmaker Luke Young for central defender Guy Branston after 76 minutes.
Striker Reuben Reid helped on Young's defence-splitting pass to enable livewire Alessandra to beat the offside trap and deftly slide the ball past Town's busy goalkeeper Matt Duke, who had gone full stretch to deny the attacking midfielder minutes before.
"I definitely think we deserved the win," Sheridan added. "We created a lot of chances, played well and were on the front foot for most of the game. I think if you do that and take games to the opposition then you get your rewards.
"I think for five or 10 minutes after half-time they had a good spell and we got a little bit sloppy and Luke (McCormick) had one or two shots to save but after that I thought we created lots of chances.
"Their 'keeper has made some outstanding saves.
"The goal to finish and win the game was an excellent move. I like my substitutes to change the game and Youngy's played four or five passes when he has come on, which no-one really did in the whole game.
"The pass for the goal was an early ball into the striker, which Reuben likes. Reuben's first touch is to Lewi and it's in the back of the net. Four touches, three players and it's in the back of the net.
"He's just picked his spot and it's just a little side foot into the corner. When he missed his chance that came across the box earlier I thought here we go nil-nil again but full credit to the players."