Thistle's cup dream is over. 

The Jags were just 13 minutes away from a famous win but an error from Niang who had been oustanding up to that point give Shankland the chance to equalise. 

Extra-time looked certain when another defensive error gifted Clark the chance to score a winner they scarcely merited. Thistle though will rue to great chances just before half-time that had either been taken would have given Thistle a two goal advantage at the break. 

A great cross from Penrice causes United all kinds of problems but Thistle can't force the ball home with the flag going up for offside in any case. 

That looked like a foul on Murray about 10 yards outside the box but there is no free kick. 

Niang has to come off with a knock. 

Disaster for Thistle and in particular Niang and Wright who gift Clark the easiest of goals. Harsh on Thistle who have contributed so much to this game but it has been two errors that have proved, or look like proving, to be their undoing. 

Thistle clear as we go into injury time. 

Murray's free kick goes all the wide to McKenna on the right. He and Rudden try to get the ball over but it goes out for a goal kick. 

Rudden wins Thistle a free kick in a dangerous position near the left corner of the box. 

Neither Murray or Graham manage to get a shot at goal as Thistle press. Docherty does but he lifts the ball tamely over the bar. 

It's careless from Thistle and Niang presenting Shankland with the opportunity that he wasn't likely to pass up. 

Murray have moved to the right after Tiffoney's forced withdrawal with Penrice fitting in on the left. 

There is a furious reaction from the Thistle bench as Brian Graham finds himself on the deck. Graham gets up and he too is furious and Kenny Arthur is shown a yellow card as tempers threaten to get out of control. We couldn't see what happened that so angered so many Thistle people. 

Penrice comes on for an injured Tiffoney. 

Into the final 20 minutes. If only there was a noisy Thistle support to help the players in this final quarter of the game. 

A Chalmers cross comes off the foot of Clark and out for a goal kick. 

Murray finds Gordon at the edge of the box but his pass is poor and United break. 

Tiffoney cuts across the face of the United box but isn't able to find a Thistle player or manage a shot. 

United to break when McKenna's throw is cleared but they make poor use of the ball. 

Gordon forces a mistake from the United defence simply by chasing a long ball and Thistle win a throw deep in the United half. 

Shankland and Chalmers try to combine at the edge of the box but Chalmers makes a mess of things and Thistle have a goal kick. 

An Edwards header is a long way off target. 

It's a poor corner from Bannigan as well. 

After two Tiffoney corners Bannigan takes this one. 

Tiffoney, who has switched to the right hand side since Murray came on, wins a free kick near the halfway line and a little bit of sting is taken out of the game. Thistle have been under relentless pressure since the start of the second half. 

Thistle are still in front but we're not sure how. The ball is cleared off the line with frantic United protests that the ball had crossed the line. At first glance it looks as if they may well have a case. 

Wright makes a great save to deny Shankland. 

The ball runs away from McNulty and out for a goal kick as the ball is played deep into the Thistle box. Thistle could do with seeing some possession of the ball at the moment. 

The corner is deep towards the back post. A United head gets to it but the ball drops harmlessly wide of goal. United have started the second half firmly on the front foot. 

Play is halted for Wright to receive a spot of treatment after being caught as the corner comes over. 

Early chance for United. Shankland's shot is blocked but spins into the path of McNulty whose effort goes over via a deflection as a corner is awarded. 

We're back underway. 

Thistle have a deserved first half lead thanks to Scott Tiffoney's headed goal after 24 minutes. 

It could, and probably should, have been even better with Brian Graham and Shea Gordon misses great chances to extend that lead in the closing stages of the first half. 

Another great chance for Thistle. This time it is Gordon that has the opportunity but he lifts the ball over the bar when anything under the bar would surely have produced a goal. 

Thistle miss a magnificent chance to go 2-0 up. Cardle finds Gordon down the right. There's no flag for offside and Gordon lays a great ball across the face of goal that Graham at the stretch can't divert into the net. 

Sporle is able to get his head to a cross from the right and Wright is required to make his first save of the afternoon but it is an easy save to complete. 

Foster reads the situation well and nods the ball back to Wright from the edge of his own penalty box. United pressing as we near half-time. 

Niang up for the corner gets his head to Cardle's good corner but he heads across goal rather than towards the United goal and the ball is cleared. 

Shankland gets in behind the Thistle defence but the flag is swiftly up for offside. 

Not the best of free kicks from Cardle and he tries to curl it deep to the back post but he gets too much on the ball and it goes behind. 

Thistle will have a free kick a few yards away from the right hand corner of the United box. 

Good defending from Niang when faced with Shankland inside the box. The defender prevents the United striker from getting anywhere near the ball as it goes out for a goal kick. 

United can't deal with a long throw from McKenna and the ball drops nicely in front of Tiffoney and he nods the ball home from inside the 6 yard box. You can't argue that Thistle don't deserve that lead. 

It's another good corner from Cardle but United clear and break quickly. McNulty eventually manages to get a shot at the Thistle goal but he drags his effort well off target. 

There is a real scramble inside the box when Cardle's corner comes over. Niang nods the ball towards the goal but the ball is cleared. Cardle collects the ball out wide again when United do clear but this time his cross is poor. 

Thistle have the game's first corner. 

Thistle look for a penalty as Gordon tries to connect with a misjudged headed pass back from Bolton and is challenged for Mehmet for the ball. 

Tiffoney pushes a pass to Graham to his left. Graham lifts a cross into the danger area but can't pick out Gordon's run into the box. Another positive move from Thistle though. 

Thistle have the ball down by the United corner flag but McKenna is penalised for a tug on Sporle. 

Tiffoney manages to get a shot away from the edge of the United box but he drags it wide of Mehmet's right hand post. Thistle starting to get into this game. 

First bit of pressure from Thistle and Tiffoney has the ball at the left hand corner of the box but his shot is blocked by Fuchs who is back defending. 

Dochert gives the ball away to Fuchs and he shoots from the edge of the box but Brownlie is across quickly to block. United have had the better of the opening exchanges with Thistle not seeing much of the ball. 

After a false start the home side get this Scottish Cup tie underway. Thistle shooting towards the traditional home end in the first half. 

It's Scottish Cup day again and with 2021 being the 100th anniversary of our, to date, solitary Scottish Cup win The Jags are wearing a special anniversary top this afternoon and, to this reporters much delight, are wearing 1-11 on the back of those jerseys. 

That starting eleven shows no fewer than 7 changes from the side that drew with Forfar on Tuesday night and of the 4 that do keep their starting places only Stuart Bannigan played the full 90 minutes in midweek. 

The seven players that step back into the starting eleven are Kieran Wright, Ciaran McKenna, Richard Foster, Darren Brownlie, Brian Graham, Shea Gordon, Scott Tiffoney. 

It can be argued that Tuesday's fixture at East Fife is of much greater importance to Thistle than this afternoon's but right now, with kick-off less than 30 minutes away, focus is firmly on creating a cup shock. 

This afternoon's tie is played, don't forget, to a finish with extra-time and penalties if required.