Kenny Arthur needed to look sharp to punch away a Derek Adams free kick and he was the Jags saviour again when Pearson had a snap shot from the edge of the box.
Thistle took heart from not being behind and came back into the game. A couple of shots were blasted wildly into the unused terrace behind the goal.
We were playing three at the back with Daniel Sengewald making a start. He was expected to dominate in the air but he looked shaky and poor throughout. Not for the first time, we sold a goal when the game was at a crucial stage. A corner was swung in and Martin Hardie was given acres of space to head home from about six yards.
It was hoped that the half time break would give us a chance to regroup. Not for the first time though, we came out for the second half looking lethargic. Thistle came close through Britton and killed the game off within six minutes of the restart. The defence swarmed to the right of the box and when the ball was played across to Burns, he had a simple task to beat Woods.
The heads could have dropped but we fought hard and created more chances. Substitute Lehmann missed two glaring headers, Kemas had a shot saved and McFadden had a good effort blocked. Things took another turn for the worst when Leitch was sent off for a second bookable offence.
We continued to push forward but Thistle played well on the break and could have added another couple to the scoreline. The news from Rugby Park that Dundee United had scored a late winner merely added to the gloom. Terry Butcher must be tearing his hair out - we could have won today on the balance of play - but individual mistakes cost us. We are desperately in need of some kind of win but no one can see where it is coming from. It will be a very pessimistic travelling support going to Pittodrie on Wednesday.