Gretna will probably be happiest with the share of the points from their two closest rivals.
Neither side were able to take control of the game in the early stages, and it was a full 11 minutes before the first chance. This fell to Thistle when Paul Ritchie did well to dispossess two defenders and break clear, but he would be disappointed only to shoot into the side netting from six yards.
Despite a lot of midfield action, chances were still at a premium and Morton's first real effort on goal came in the 27th minute when Chris Millar fired a 22-yard shot which was well saved by Kenny Arthur.
Thistle made a deserved breakthrough on 33 minutes when Jimmy Gibson, J fired an unstoppable 22-yard free-kick which took a slight deflection en route into the far corner.
Thistle almost doubled their lead on the stroke of half-time when Ritchie's net-bound header was headed off the line by Kevin Finlayson.
Morton appeared fired up by the half-time team talk and were in the ascendancy right from the start of the second half. After 52 minutes Millar should have done better than fire wide from close range, and four minutes later James McAlistair's cut-back caused confusion in the Thistle defence before eventually being cleared.
Morton continued almost constant pressure on the Thistle goal, and it came as no surprise when they equalised after 81 minutes. John Adam fired a pin-point perfect cross to the head of Derek Lilley, who gave Arthur no chance from 10 yards.
Both sides had further half chances in the dying moments but had to settle for a point apiece, and it now looks like the play-offs beckon for both Morton and Thistle.