Thistle's season continued to go downhill after a third successive home defeat by Hamilton.
Thistle started brightly and their first chance fell after only four minutes when Juan Ramon Escalas should have done better than shoot wide from 16 yards. Thistle continued to put pressure on the Hamilton defence, but the Accies back line were equal to the task.
Hamilton took the lead with their first real chance after 13 minutes when a Mark Corcoran corner found Brian McPhee unmarked and his header from 10 yards gave Kenny Arthur no chance.
This appeared to rattle Thistle and it took some time for them to create another chance which they did after 28 minutes. Billy Gibson's run and shot was blocked only for the rebound to fall to Leigh Hinds, whose 20-yard shot was deflected for a corner. From the corner Adrian Madaschi's header looped agonisingly over the bar and on to the top of net.
Hamilton almost doubled their lead after 34 minutes when powerful play from Pat Keogh saw him firstly dispossess Grant Murray and then fire a 22- yard shot that Arthur brilliantly tipped over the bar.
The second half saw Thistle determined to save their season and Ken Milne had a chance after 48 minutes when he cut in from the wing, but his low 18-yard shot was comfortably saved by David McEwan.
Further chances were few and far between as Hamilton appeared comfortable in holding on to the victory and Thistle unable to change things, although Escalas on 71 minutes did see his shot deflected for a corner. The last chance of the game fell to goalscorer McPhee, but his effort was smothered by the onrushing Arthur.
The final whistle was met with resounding boos from the home support and cheers from the visitors, as Accies are now clear from the relegation zone and Thistle will spend Christmas in a position that at the start of the season seemed unthinkable.