The Dons suffered their first defeat of the pre-season as a rugged Barnet side ran out winners in a competitive affair at Underhill.
A Mark Gower penalty two minutes into the second-half sealed the win for the recently relegated Bees after Wayne Purser's run was halted by Des Byrne.
Underhill is still very much a Non-League ground and possesses a sloping pitch of Alpine-like proportions that the home side used to their full advantage in the second-half.
Paul Heald pulled off a fine save after just two minutes to prevent Ben Strivens giving John Still's side the lead, but that aside the Dons dominated the opening period with David Nielsen, Michael Hughes and Des Byrne all going close.
However, the Dons went in at half-time with nothing to show for their dominance and the introduction of the pacy substitute Purser changed the complexion of the game.
Barnet had the lion's share of the second-half, and could well have doubled their lead had it not been for the alertness of Ian Feuer in the Dons' goal.
Overall, a disappointing night for the Dons, but there were some positive points with Mikele Leigertwood impressing at the heart of defence with a very accomplished performance.
Head coach Stewart Robson said after the game, "We didn't really perform tonight. I felt at times we didn't do the basic things and we got punished.
"Their goal was a poor one from our prospective as we let the player run half the length of the pitch and gave away a penalty."