Scorers: Stranraer - Turner (79); Ayr United - Shankland (8 and 54), Moffat (39) and Forrest (49 and 62)
STRANRAER went down to their third defeat in a row as Ayr United made it three derby wins out of three this season.
The Blues, who have been forced to part with Tom Lang, Danny Stoney and Ryan Wallace in recent weeks, made one change from the side that lost 3-0 to Raith Rovers three days earlier.
Liam Dick had completed a move to Dumbarton, which allowed Christopher McGowan to make his full debut.
In comparison to Stranraer's worries, Ian McCall was able to leave top scorer Craig Moore on the bench and yet still have Michael Moffat and the free-scoring Lawrence Shankland in the team.
It would be ex-Aberdeen man Shankland who opened the scoring after just eight minutes.
Declan McDaid sliced open the home defence and, although Cameron Belford managed to partially blocked Jamie Adams' shot, the ball looped into the air with Shankland nodding home from close range.
Stranraer enjoyed plenty of possession in the first half in front of more than 600 home fans, and Kyle Turner tested Jordan Hart on more than one occasion.
Soon afterwards, a goal line clearance prevented a goal from Turner's corner before Ayr doubled their advantage in stunning fashion.
Moffat, a regular goalscorer against the Blues, had plenty to do but curled a delightful effort round both Scott Robertson and Belford, which clipped the inside of the post before nestling in the back of the net.
Like the trip to Kirkcaldy, it was a harsh lesson in ruthless and clinical finishing, with Stranraer more than matching the Honest Men but finding the game increasingly out of their reach.
Any chance of a comeback was quickly killed off in a 15-minute spell when the visitors took advantage of some poor home defending to add three further goals.
Alan Forrest was the first to add his name to the scoresheet when he seized on some slack defending from Morgyn Neill.
The midfielder robbed the defender of the ball, powered into the box and kept his cool to beat Belford.
Five minutes later and it was 4-0 with the defence again caught napping as a long ball over the top found Shankland, who grabbed his second of the day.
And, just after the hour mark, Stranraer's misery was complete when Forrest cut in from the left before beating Belford for a second time.
Stevie Farrell had already made three changes before the fifth goal went in with David Gray, Cameron Elliott and Stephen Okoh replacing Robertson, Neill and Paul Woods.
The three substitutes added some spark to the team and Okoh came close to scoring his first goal at Stair Park when he poked narrowly wide following Turner's corner.
Then, with ten minutes left, it was Turner, who, fittingly, got his name on the scoresheet.
Elliott did well out wide and picked out Turner with a low cross, with the midfielder sliding the ball beyond Hart.
The goal was more than merited, with the Blues now aiming to end their winless streak when they travel to Hampden Park.
Stranraer: Belford, Robertson (Elliott 55), Neill (Gray 57), Woods (Okoh 55), Bell, Anderson, McGowan, Turner, Beith, Hamill, Thomson.
Not used: Agnew, Scott, McKinlay and McLaren.
Ayr United: Hart, Higgins, Boyle, Rose (Faulds 69), Moffat (Moore 63), Forrest (Hilton 83), McDaid, Ferguson, Adams, Shankland, Reid.
Not used: Gilmour, McGuffie, McCowan and Avci.
Referee: Grant Irvine
Photos: Stranraer FC