Thistle played host to local rivals Muchty Bellvue in the Tom McIntyre Memorial Cup, but a dismal performance saw the Balmullo side succumb to their biggest defeat of the season.
The deadlock was broken with a little over seven minutes on the clock when former Thistle player Honeyman curled a tremendous effort past Henderson.
With 17 minutes gone Thistle were back on level terms when a Moir free kick was sliced into the path of Petrie with the big striker making no mistake.
Just on the brink of half time Thistle had keeper Henderson to thank for keeping the score lines level when he produced a stunning save to deny Honeyman.
Thistle’s top scorer Barnes was being forced to feed off scraps but he came close to grabbing a goal after 77 minutes as he latched onto a neat through ball from McLaren.
Robertson in the Muchty goal again produced the goods with a good save.
Just a minute after surviving this scare Muchty went up the park and grabbed the goal to put them in the lead.
Gough partially cleared after a goalmouth scramble, but inexplicably Thistle switched off as Dunsmore slipped the ball through to O’Leary who fired past a ruck of bodies and into the net.
Worse was to follow five minutes from time as Thistle conceded a third as Cruickshank took advantage of sloppy defending to head home.
Thistle’s woes were completed when Barnes missed a penalty.
Alba Mortgage Solutions man of the match – Gavin Henderson.
Thistle – Henderson, Provan (Buchanan 85), Gough, Carson, McShane, Shepherd (Ireland 66), McLaren, Moir (Ross 33), Jukes, Barnes, Petrie
Subs – Watters, Halley.
Tomorrow (Saturday) Thistle are on Fosters Scottish Cup duty when they play host to Bridge of Earn in the third round.
Kick off 2pm at Balmullo.