FRUSTATION and disappointment barely describes the atmosphere in Paisley last night as St Mirren missed out on qualification to the last 16 by a solitary goal.

Leading by three at half-time, it seemed certain they would score just as many in the second half but they failed in their mission and Ayr United have joined group winners Hamilton Academical in round two.

It was a mystery to manager Alex Rae, who also felt a penalty should have been awarded when Lawrence Shankland was barged off the ball by Gordon Donaldson just before half-time.

He said: “We created numerous chances and my only criticism of the boys was they were not clinical enough.

“The intensity from the beginning was great. The boys were a threat from the wings, so overall I was relatively pleased with the application after a poor result the previous week.

“For the life of me I can’t understand why the referee has not given a penalty for the challenge on Shankland. It’s such a poor decision it beggars belief.

“Outwith that we had efforts cleared off the line, so it’s disappointing to get nine points and not progress. It’s a sore one to take but it puts us in good stead for next week when we will have a tough task against our local rivals.”

There were positives as Lewis Morgan and Tom Walsh were terrific in the wide areas, with Walsh grabbing his first goal for the club in between Shankland’s header and Jack Baird’s strike.

Morgan teased and tormented the League Two side most of the day and set up the opening goal in 12 minutes with a measured cross from the right side of the City box to the back post, where Lawrence Shankland scored with a simple header.

Shankland should have scored a second goal in 25 minutes when David Clarkson cleverly headed Morgan’s cross back across goal for what seemed a simple finish but the striker headed straight at Calum Antell from point-blank range.

The Aberdeen loanee, however, made amends five minutes later when he burst forward to release Walsh on the left side and the winger, on loan from Rangers, cut inside onto his right foot to drill a low shot into the left corner.

There was some controversy over the third goal in 33 minutes as referee Steven Kirkland allowed play to continue while City captain Mark McConnell lay injured in the penalty area as Saints pushed and probed for an opening,

They got it when Shankland’s shot was deflected into the path of Baird who fired a low shot into the net from 12 yards having remained in attack following a Stevie Mallan corner.

In first-half injury time Jordan Caddow prevented a fourth goal when he cleared Andy Webster’s powerful header from just in front of the line following another dangerous Mallan corner.

The scene was set, it seemed, for more of the same in the second half but the Paisley side could not find the same openings.

Substitutes Ryan Hardie and John Sutton came closest when the former had a left shot cleared off the line by Jordan Caddow in 75 minutes then the latter’s right foot shot was brilliantly saved by Antell.

It was agony for the supporters as they knew one more goal would take them through but Saints just could not provide it.

The debut of Craig Beattie for the League Two side was certainly uneventful although he had only trained once with his new employers.

Ten years ago he faced St Mirren in rather different circumstances, coming on as a substitute for Maciej Zurawski as Celtic unfurled the Championship flag, and went on to play his part in a League and Cup double.

These halcyon days must seem like a lifetime ago now but his experience will surely be invaluable in the Edinburgh City’s inaugural League Two campaign.