The year that brought them the First Division crown and a return to Scotland's top table ended in demoralising fashion at Firhill yesterday as Motherwell ran out comfortable 5-1 winners, extending the Jags' winless run to nine games to leave them 10th in the standings at the halfway stage of the campaign.
The months since the title was toasted and championship flag hoisted have proven difficult for Alan Archibald's side, with their latest defeat another sore one to suffer as they prepare for a fight in 2014 as they bid to retain their top flight status.
Archibald: "It was very hard to take. I thought it was embarrassing. The second-half performance was unacceptable. We went to have a go and left ourselves wide open.
"We started very well and got the goal but Motherwell were more professional and more precise and individual errors cost us. It was probably naivety, after we scored one we went looking for more and probably shouldn't have.
"But Motherwell capitalised on our mistakes. They didn't have to work hard for their goals but we had to cut them open to get our chances."
After once again failing to break their Firhill Premiership hoodoo against Inverness on Boxing Day, Thistle went into their final fixture of the year eager to give the home crowd something to cheer about.
The Jags made the perfect start to what turned out to be a festive cracker as Steven Lawless netted the first of four goals in the opening half after just seven minutes, rounding off a slick passing move from Archibald's side with a cool finish against his former club.
Unfortunately for Thistle, that was as good as it would get as Motherwell moved through the gears and eased to a deserved, decisive victory, firing in five goals without reply to continue their impressive recent run and retain their position as best of the rest heading into the new year.
Their first came from skipper Keith Lasley, the midfielder collecting a perfectly-weighted pass from the returning James McFadden and slotting beyond Scott Fox to pull Stuart McCall's side level.
Thistle continued to play at pace and full of attacking intent, Kallum Higginbotham and Kris Doolan both going close, but it was Motherwell who would find the target again, Zaine Francis-Angol waltzing his way into the area and finishing well before McFadden netted the pick of the bunch as he lobbed Fox to put the Steelmen well in control.
IT didn't take long for McCall's men to make sure of all three points as they bagged their fourth of the afternoon, with Aaron Taylor-Sinclair the Jags culprit as Lasley cut out his poor pass from the back and Well pounced in clinical fashion, Lionel Ainsworth finding the far corner of Fox's net.
It almost got worse for Thistle when McFadden's header crashed off the bar but Motherwell didn't have to wait long to add to their tally for the afternoon as substitute John Sutton blasting home after a mistake from Gabriel Piccolo.
The visitors didn't rub any more salt into Thistle's wounds but things don't get any easier for the Jags as they get set for a trip to Celtic Park on Wednesday.
Archibald said: "It seems to be when you have a bad result you have to go to somewhere like that. We are back in today and we will try and lift their heads.
"We have to go to Parkhead and put in a performance, we owe the fans one after that because it wasn't acceptable."