Murphy drilled home in the second half after Michael Smith's looping header had given the Dons the lead before the break.
The result ends a run of four consecutive away defeats for the Daggers and Burnett admits he was forced into 'plan B' after midfielder Billy Bingham was injured midway through the first half.
"It was a brilliant finish from Rhys, that's what he does," Burnett said.
"He's scored nine now and is still top goalscorer in the league. He's getting the plaudits and rightly so, but can he be better? Yes.
"I think if we scored the first goal we would have won the game.
"Abu (Ogogo) our captain was missing, Billy Bingham went off and we had Medy Elito in midfield who did brilliantly well.
"I'm delighted that we showed strength of character. We came back at a place which isn't easy to come.
"Sometimes you have to look at it that even though we've been beaten in the last four away games, we haven't played poorly.
"If we were horrendous I'd think we'd need a bit of help.
"Possession-wise, shots on target, predominantly we've been the better team. Sometimes in the face of defeat you can take the positives from it."
- Sports & Recreation
- Billy Bingham