Jason Lee scored the winner as Notts County fought back from two goals down to end Barnet's six-game unbeaten run.
Barnet took the lead with Ian Hendon's 25th-minute penalty and doubled their advantage when Jason Puncheon tapped in the loose ball from close range.
County skipper Alan White reduced the deficit with a towering header, then Andy Parkinson's volley brought them level by half-time.
After the break Lee burst through the offside trap and finished neatly.
Barnet: Harrison, Hendon, Charles, King, Gross (Hessenthaler 83), Cogan (Graham 66), Bailey, Sinclair, Puncheon, Kandol, Vieira (Grazioli 71).
Subs Not Used: Flitney, Warhurst.
Booked: Hendon.
Goals: Hendon 25 pen, Puncheon 30.
Notts County: Pilkington, Gleeson, Edwards, White, McCann, Pipe, Somner (Ross 51), Martin (Hunt 57), Parkinson, Lee, Dudfield (Mendes 45).
Subs Not Used: Deeney, N'Toya.
Goals: White 32, Parkinson 37, Lee 55.
Att: 2,317
Ref: P Miller (Bedfordshire).