Nisbet's strong strike from just inside the area in the 76th minute at McDonald Jones Stadium on Saturday night earned a deserved victory for the Mariners, who claimed the F3 Trophy.
They tallied eight more shots and limited the Jets to just one attempt on target.
The visitors created most of the chances in the second half after a cagey first 45 minutes containing few clear-cut opportunities.
"I think it was only going to be a one-goal game once we got past that 15, 20-minute mark," Nisbet told Paramount Plus.
The win lifted Central Coast to first on the ladder on goal difference above Wellington Phoenix, who can regain the lead with a draw at home to Adelaide on Sunday.
It was a record fourth-straight F3 derby loss for Newcastle and the Mariners fifth consecutive win over their local rivals.
The Jets' winless streak extended to six matches and left the 11th-placed team with very little hope of making the finals.
It was a club record-equalling ninth clean sheet of the season for the Mariners, who rarely looked like conceding.
Central Coast have lost just one of their last 16 matches, though Saturday's performance wasn't as impressive as others earlier in that run.
"It wasn't as free flowing and (as many) chances as we want to create," Mariners coach Mark Jackson told Paramount Plus.
"I thought we controlled the game which is what we wanted to do.
"To come away from home in a derby and do that takes a lot of courage from the players and a lot of quality, but I think today probably what let us down was the final third if we're being hyper-critical of ourselves."
The Mariners Max Balard had the best chance of the opening half with his close range shot blocked by Newcastle goalkeeper Ryan Scott, who then had to push away a deflection off a teammate.
The league's leading scorer Apostolos Stamatelopoulos had the Jets only shot on target blocked by Mariners goalkeeper Danny Vukovic In the first half.
Newcastle coach Robbie Stanton told Paramount Plus he was happy with the performance and effort of his players despite being disappointed with the result.
"We've got a little bit of work to do in some areas but certainly proud of the players.," Stanton said.
"For a derby I thought we made a good account of ourself, would have liked to have a little bit more ball at times."
Central Coast wasted a number of chances in the second half before Nisbet found the target.
