Macaulay Bonne and Scott Malone both benefited from those errors from Dons players, firing the Kent side 2-0 up before Ellis Harrison headed in late on to set up a potentially enthralling finale.
But a red card in stoppage time for Daniel Harvie put paid to any late chances for Graham Alexander’s side.
Here’s how we rated the players at Priestfield.
13. Sub: Ellis Harrison - 5.5
Threw himself about as usual, and finally got his reward with his first Dons goal late in the day Photo: Jane Russell
14. Sub: Jonathan Leko - 5
A massively frustrating performance. Looked alive, but his crazy mistake in the second-half gifted Gillingham their second goal. Tried to do it all himself at times, but his great cross led to Harrison's goal Photo: Jane Russell
15. Sub: Max Dean - 6
Replacing injured Dennis, Dean gave more life up front but should have equalised just a few minutes after Harrison's goal, hitting the side netting. Photo: Jane Russell