Thistle travelled to face Kirkcaldy Rovers in the Tom McIntyre Cup section looking to make it five wins from five.
They took the lead with little over two minutes on the clock when Petrie dispossessed Crawford inside the box before slipping the ball to Barnes who duly slotted the ball through the legs of the advancing Kaye.
Thistle were made to pay early in the half when the impressive Johnston beat the offside trap to collect a Loughran ball before slotting the ball past Anderson 1 on 1.
Thistle lost the services of talisman Barnes midway through the half with a hamstring injury meaning a reshuffle but continued to apply pressure on the Rovers goal with Petrie and Jukes passing up good opportunities.
Just on the stroke of half time Kirkcaldy took the lead against the run of play when McArthur was woefully short with a pass back to Anderson allowing Johnston to nip in and slip the ball past the stranded Anderson.
After 55 minutes Thistle were back on level terms when Moir picked out Petrie and the big striker fired a pinpoint low driven shot into the net from just inside the box.
Anderson had not had much involvement in the game, however, the Thistle keeper was forced to produce a good save from a speculative Snaddon effort that looked to be heading for the top corner before the keeper tipped it over the bar.
With 17 minutes remaining Thistle got themselves back in front when Kaye sliced a goal kick into the path of Petrie who showed fine control to take the ball down and slot home for his ninth goal of the campaign.
Once again Kirkcaldy showed resolve and bounced back with an equaliser just two minutes after going behind when Conner shook off the attentions of McArthur to head home from a corner.
Thistle had one last chance to take the full points when great play from Petrie allowed him to put Cameron through on goal but once again Rovers keeper Kaye produced an excellent stop. Alba Mortgage Solutions man of the match – Liam Carson.
Thistle – Anderson, Ireland, Gorgon (Shepherd 59), McArthur, Carson, Jukes, Thomson, Gough, Cameron (Palacios 85), Barnes (Moir 28), Petrie.
Subs – Ross, Murray.
This weekend Thistle travel to Kinross to face Fossoway in the quarter final of the Taylor Sullivan Funeral Directors Challenge Cup.