Queen of the South ended an 11-match winless run in the Championship with victory in Paisley to plunge St Mirren further into relegation trouble.
ST MIRREN 0 QUEEN OF THE SOUTH 3 HT: 0-1 Scorers: Queens - Dobbie (45+1) Thomson 82 MacKenzie (85 og) Attendance: 3105 Referee: M.Northcroft
Stephen Dobbie's 17th goal of the season, created by new Queens captain John Rankin, put the visitors ahead.
Kyle McAllister thumped a shot against the bar as Saints threatened an equaliser after the break.
But another debutant, Celtic loanee Joe Thomson, made it two with a tap-in before Gary McKenzie's own goal.
Defeat leaves Saints still stranded seven points behind Ayr at the foot of the table.
Queens remain in seventh, level on points with sixth-placed Dunfermline but only one adrift of Raith Rovers.
New signing Rankin engineered the opening for Dobbie's opener just before half-time with a fine pass and, when Dobbie's effort hit a post 10 minutes from time, Thomson had an easy task from the rebound to seal victory.
The third arrived three minutes from time when substitute Lyndon Dykes' effort went in off McKenzie.
As well as Rankin and Thomson, Queens - who had not won a league game since 17 September - also gave a debut to Dom Thomas, on loan from Motherwell.
Images courtesy of www.qosfc.com