Dumbarton moved up a place to eighth in the Championship as Queen of the South's miserable slump continued.
The Sons scored against the run of play when Ryan Stevenson fired a shot into the top corner from 25 yards.
Garry Fleming then converted a penalty for the visitors after Jamie Hamill pushed Joseph Thomson.
Derek Lyle netted from close range on 80 minutes to give Queens hope but the one-time leaders could not prevent a sixth consecutive league loss.
It was just a third Championship win of the season for Dumbarton, who survived pressure before Stevenson's spectacular opener.
Mark Millar fired wide before Stephen Dobbie had an attempt saved and then shot over the crossbar, while Lyndon Dykes and Grant Anderson also went close for the hosts, who stay sixth in the table.
Images courtesy of www.qosfc.com
Queen of Sth
- 1Robinson
- 2Hamill
- 4Dowie
- 5Brownlie
- 3Marshall
- 7AndersonSubstituted forLyleat 63'minutes
- 8MillarBooked at 43minsSubstituted forMoxonat 66'minutes
- 17Pickard
- 39Carmichael
- 11Dobbie
- 25Dykes
Substitutes
- 6Higgins
- 9Lyle
- 16Hooper
- 19Moxon
- 20Atkinson
- 29Bell
- 35Brotherston
Dumbarton
- 27Martin
- 17Smith
- 5Buchanan
- 14BarrBooked at 23mins
- 12Harvie
- 7Todd
- 22StirlingSubstituted forLydenat 90+3'minutes
- 4Thomson
- 6StevensonSubstituted forMcCallumat 85'minutes
- 9FlemingSubstituted forPettigrewat 79'minutes
- 10Thomson
Substitutes
- 1Brown
- 2Pettigrew
- 15McCallum
- 16Lyden
- 24Crawford