This was County's third loss in a row - their worst sequence of the season - and in losing to the better team they were guilty of crucial defensive lapses.
Wycombe began at a high pace, frequently testing a hard pressed Notts defence, and it was only a matter of time before they scored.
When the goal arrived on 32 minutes it was preventable. Veteran Tommy Mooney instigated the move and Notts were slow to deal with his cross into the box for Dean Bowditch to take full advantage of the hesitancy and shoot low past Kevin Pilkington.
Most of the danger flowed down Wycombe's right flank with Danny Senda and Kevin Betsy creating havoc but the visitors were unable to add to their advantage.
Notts were brighter after the restart and when they levelled on 54 minutes it was defender Brian O'Callaghan's first for the club.
Julien Baudet's initial effort came back off the defensive wall and O'Callaghan's deflected drive trickled over the line.
Wycombe continued to play with self belief but their winning goal was the softest imaginable.
Striker Ian Stonebridge came off the bench to replace ex-Notts man Stefan Oakes, jogged into the penalty area and headed home from Clint Easton's free kick completely unchallenged.
It was a crazy goal by which to lose the match and after it Notts never looked capable of saving a point.