Updated at 19.13

HAVING JOINED Motherwell from Bohemians recently, Ross Tierney did not take long to make an impact at his new club.

The Ireland U21 international was introduced in the 76th minute off the bench and won a penalty as his side earned a dramatic win today.

Fellow Ireland U21 player Oisin McEntee came off the bench for the visitors, while ex-St Pat’s player Jake Carroll started for the Scottish Premiership side and former Wexford footballer Darragh O’Connor was an unused sub.

Liam Donnelly’s late extra-time strike sealed a dramatic Scottish Cup comeback for Motherwell as they came from behind to defeat Championship side Morton.

The two sides could not be separated after a closely contested 90 minutes and another half-hour was required to find a winner.

Morton broke the deadlock with the last kick of the first period of extra time as Robbie Muirhead’s curling effort nestled into the far corner but the Steelmen showed their Premiership class to complete a dramatic late turnaround in North Lanarkshire.

Top scorer Kevin Van Veen dispatched from 12 yards to pull Motherwell level in the 109th minute before Donnelly’s last-gasp stunner lifted the roof off Fir Park and sealed a place in last 16 for Graham Alexander’s side.

Well’s Connor Shields had the first chance of the game in the 10th minute as he raced down the line on the break, with his goalbound effort forcing Jack Hamilton into a tremendous save.

Motherwell enjoyed the bulk of possession but struggled to create any clear chances in the first half. Barry Maguire’s low drive from the edge of the box was brilliantly saved by Hamilton in the 23rd minute before Jordan Roberts’ venomous strike went narrowly wide.

Morton’s first chance came on the stroke of half-time when Lewis Strapp’s long throw evaded everyone at the near post and fell to Gavin Reilly, who adjusted his body well 12 yards out to hit a fierce half-volley that was beaten away by Motherwell goalkeeper Liam Kelly.

The second half was a cagey affair with chances few and far between, although Shields should have done better from a Stephen O’Donnell cross as he headed straight at the Ton goalkeeper from close range.

Alexander turned to Van Veen for inspiration as he came on to replace Kaiyne Woolery and within minutes of coming on, he stung the palms of Hamilton after dancing between Morton defenders on the edge of the box.

Van Veen missed a gilt-edged late chance to win it in normal time as he found himself through one-on-one. Hamilton was once again equal to the task as he made another sublime save to send the tie to extra time.

The Championship side took a shock lead as substitute Muirhead cut in from the left and his curling effort nestled into the far corner beyond Kelly.

Morton looked on course to pick up their first win at Fir Park since 1922, but Motherwell were awarded a spot-kick in the 109th minute after Tierney was pushed over inside the box by Michael Ledger and Van Veen’s emphatic penalty flew past Hamilton.

The game looked destined for a penalty shoot-out until Donnelly’s vicious strike in the dying embers from the edge of the box flew into the roof of the net to earn the Premiership side a last-16 spot.

Elsewhere in Scotland, two second-half goals from Cork native Jaze Kabia helped Falkirk to a 2-0 win at 10-man East Fife.

It was only announced yesterday that the former Shelbourne winger had joined the club on loan from Livingston.

East Fife sit bottom of cinch League One and have now failed to win in their last 10 games after Kabia struck early in the second half and in stoppage time to seal all three points, after home keeper Jude Smith had been sent off in the 16th minute.

Clyde bounced back from a goal down to share the spoils in a 1-1 draw with Queen’s Park.

Michael Doyle opened the scoring for the visitors, heading home a corner played in by Ireland U21 international Luca Connell before David Goodwillie equalised from the penalty spot to make sure Clyde stay sixth while Queen’s Park remain in fourth.

Additional reporting by Paul Fennessy