Callumn Morrison swept home to put the Pars ahead in the 23rd minute but just over a minute later a succession of mistakes in the home backline allowed Aidan Fitzpatrick to tee up Ben Stanway to net the leveller.

Both teams had chances to claim victory ahead of Friday evening’s second leg at Firhill, though neither were able to find a winner as an end-to-end encounter finished level.

Dunfermline started brightly, winning a succession of corners before Chris Kane forced Josh Clarke into a smart low stop with a snap-shot from the edge of the box.

The deadlock was broken in the 23rd minute after Andrew Tod latched on to a long free-kick before cutting back for Morrison to slot home.

On the touchline, Pars boss Neil Lennon urged for calm, but his side would be pegged back just 79 seconds later.

Defensive mistakes from Josh Cooper and Alfons Amade presented Fitzpatrick with the chance to feed Stanway, who kept his composure to slot beyond Aston Oxborough.

Morrison was unable to keep his volley down as the home side looked to restore their advantage.

In the 43rd minute, Matty Todd passed up a good chance when he tamely directed Morrison’s cross to the back-post into the grateful arms of Clarke.

The home fans were certain they should have had a penalty on the stroke of half-time after Todd hit the deck under the challenge of Fitzpatrick — but referee Duncan Nicolson awarded a goal kick.

Fitzpatrick thought he had fired the Jags ahead in the 47th minute when he dispatched the ball beyond the home keeper following a defensive lapse from Tod — but his celebrations were cut short by the offside flag.

Thistle were beginning to look dangerous and Stanway was denied by an excellent save from Oxborough after Logan Chalmers forced an error from Kieran Ngwenya.

It took a good stop from Clarke to parry away Robbie Fraser’s free-kick in the 54th minute. Morrison was quickest to the rebound, though after going to ground, his half-hearted appeals for a penalty were waved away.

With Dunfermline appearing to be taking control, Wilson made a triple change with 25 minutes remaining — introducing Samuel, Cameron Logan and Robbie Crawford for Tony Watt, Ben McPherson and Tsoanelo Letsosa.

Cooper came agonisingly close to finding the net after 75 minutes, gliding past Logan before curling an effort inches past a post with the keeper scrambling.

Substitute Keith Bray lashed wildly over with nine minutes remaining as Lennon’s men searched for a winner.

In the final minute, Oxborough was the hero for Dunfermline as he superbly pushed away Fitzpatrick’s goal-bound strike before Samuel headed wide from close range.

The Pars keeper was fortunate in added time after being caught out by Crawford’s attempt, but the ball trickled inches wide of the target.

There were more nervy moments during three minutes of added time, with several crucial blocks from Ngwenya helping the hosts hold firm ahead of Friday’s decisive second leg.