Steve Claridge scored his first goal for Portsmouth to give Alan Ball a much needed victory in Pompey's fight against relegation.
The on-loan Leicester City front man scored with a 14th minute header from close-range to mark his fifth game for his home town club with a vital goal.
Claridge was released by Portsmouth as an 18-year-old but was signed to help the relegation-haunted club escape the drop to Division Two.
He almost grabbed the second in the 18th minute when he turned sharply and fired a shot past Eric Nixon - but saw his effort ruled out for offside.
Stockport battled back into the game and it needed several fine saves from goalkeeper Aaron Flahavan to keep his side in it.
Flahavan, selected in preference to long-serving Alan Knight for the first time since Ball returned to the club, first denied Brett Angell.
Angell, himself a former Portsmouth player, thought he had scored with a close-range header in the 38th minute but Flahavan managed to parry it wide.
After 44 minutes, Jim Gannon volleyed in from 30 yards and Flahavan somehow managed to recover his footing to catch a sharply dipping effort.
Flahavan again denied Angell in the second-half and also kept out an effort by Chris Byrne.
Substitute Martin Nash had the best chance to equalise for Stockport when he found himself in space on the edge of the six yard box.
But Nash somehow managed to side-foot his shot wide to the frustration of manager Gary Megson.
Referee Barry Knight was busy with bookings flying around as tension mounted and in the first-half he cautioned Portsmouth's Australian international John Aloisi for a needless challenge on Mike Flynn.
Alan McLoughlin and substitute Mathias Svensson were also booked by the Kent official.
For Stockport there was a booking for Kevin Cooper for a nasty foul on Sammy Igoe.
A crowd of 8,622 gave Portsmouth a rousing standing ovation as Ball celebrated his first victory since returning to the club - but Pompey still find themselves pinned to the foot of the First Division table with 15 matches remaining to save themselves from the drop.