This local derby was, as expected, a fiercely competitive battle, and certainly not a game for the faint-hearted.
The early exchanges were even and although Haslemere eventually took the lead with the first of a brace of goals for skipper Chris Stokes, it was only after their 'keeper, Dan Hollyman, had made two or three good saves.
A goal of remarkable skill by Marcus Handley put Petersfield on level terms and it remained 1-1 at the interval.
Meanwhile, Petersfield had lost key forward Dean Tutt after a whack on the head, causing him to be replaced by Tom Martin.
They also lost accomplished left-back Gary Tutt with a gash above the right eye which needed hospital treatment.
The second half started superbly for Haslemere. Andy Bray was caught cold in the left-back role and Dhiren Patel, who also took a 'tap'on the head' initiated a flowing move that resulted in Guy Jones restoring the visitors' advantage.
The Blues then built an unassailable lead from three clinically executed short corners, with Duncan Berry and Ed Rogers, twice, providing the finish.
Graham Stoper replied with a good goal, but Petersfield were becoming increasingly frustrated and three of their more experienced players were sin-binned, ruling out any chance of a late revival.
Haslemere increased their lead with ease playing against eight men, Stokes scoring his second of the game.
Two of the youngest players on the field, Tom Martin and Graham Stopher, had excellent games for Petersfield.
For Haslemere, this morale-boosting result could mark an upturn in their fortunes.
"I feel we have definitely turned the corner," said long-serving Dhiren Patel who has resumed coaching duties at Woolmer Hill. "The confidence is coming and we have two or three players to come in and strengthen the squad."
This Saturday, Petersfield travel to Fleet who, like Haslemere, were relegated from the Regional league last season. Haslemere are home to Trojans.