Lennon Miller held his nerve to net an injury-time penalty and earn Motherwell a place in the semi-final of the Premier Sports Cup with a 2-1 victory over Dundee United.

It looked as if a sensational leveller from former Well striker Louis Moult was set to send the game to extra time, before the hosts were awarded a spot-kick in added time.

Miller was tasked with netting from the spot and he made no mistake in sending the United keeper the wrong way.

Zach Robinson had earlier opened his scoring account for Motherwell when he blasted into the top corner in the final seconds of the first half.

Kristijan Trapanovski looked in the mood during the early stages, curling an effort wide of the target and then testing Aston Oxborough with a low drive.

Chances were at a premium and it took the hosts until just after the half-hour mark to register their first shot on target – a tame strike from Robinson that trickled into the arms of Jack Walton.

The opening goal arrived in added time of the first half and would come in stunning fashion.

Miller’s strike was well saved and when the ball eventually broke the way of Robinson, he lashed it high beyond Walton.

Robinson passed up a good opportunity to double his tally when he leapt highest to meet a Ewan Wilson cross, though his header would sail harmlessly wide.

At the other end, Ross Docherty let fly from long range and would watch on with agony as the ball flew inches past the post.

Jim Goodwin introduced Moult and Sam Dalby to try to strengthen his attack, however, the better chances continued to fall to the hosts.

A crucial intervention denied Miller and the youngster would then see his goal-bound attempt cleared off the line.

With 13 minutes remaining, it required a wonderful stop from Oxborough to keep the home side ahead.

Two United substitutes combined when Moult sent Dalby through on goal – but the outstretched leg of the Steelmen keeper would divert the ball over the crossbar.

Just as it looked like Motherwell had survived, they would find themselves facing extra time after their former fan favourite returned to haunt them in the 83rd minute.

Yet again, Dalby and Moult combined and on this occasion the former Well striker would slam an unstoppable half-volley into the top corner.

There was more drama two minutes into injury time, with the award of a penalty for the hosts after Luca Stephenson felled Moses Ebiye.

Miller stepped up to take the resulting kick and remained the coolest man inside Fir Park as he rolled the ball into the net to send the home fans wild.