In-form Morton beat Motherwell 2-1 in the Scottish Gas Scottish Cup fifth round at Cappielow after Robbie Muirhead’s first-half corner caused chaos in the visiting defence.
Muirhead’s inswinging corner caught out Liam Kelly, who palmed the ball out but saw it ricochet over the line off team-mate Harry Paton.
The home side had used their wind advantage to good effect in the first half and kept Motherwell under pressure while the Steelmen struggled to offer any real attacking threat.
George Oakley doubled Morton’s lead after the break and Motherwell’s comeback attempts were too little, too late.
Substitute Jack Vale pulled one back with a deflected effort in the 85th minute but Dougie Imrie’s side deservedly held on to become the first club in the quarter-finals.
Motherwell had beaten Morton four times in cup competitions in the previous six seasons but their last trip to Cappielow in 2015 resulted in a League Cup defeat which spelled the end of Ian Baraclough’s time in charge.
Both sides came into the game on the back of 5-0 victories and unbeaten runs. Morton’s 12-match streak without defeat was twice as long as Motherwell’s and had taken them from bottom of the cinch Championship to fourth spot.
Kelly appeared troubled by the windy conditions early on. The Motherwell captain kicked one goal kick straight out of the park and soon fumbled Alan Power’s free-kick but gathered under pressure.
Morton continued to pose problems from set-pieces, including Lewis Strapp’s long throws, and they had a great chance after keeping the pressure on from one of those dead-ball situations. Two Morton headers set up Oakley who volleyed off the bar from six yards.
The home pressure paid off in the 35th minute when Muirhead’s corner eventually found its way in.
Ryan Mullen made his first save when Blair Spittal curled the ball into the Morton goalkeeper’s hands but the home side soon doubled their lead in the 55th minute.
Paul McGinn’s heavy touch put Motherwell on the back foot and Power quickly found Oakley with a forward pass. As Calum Butcher backed off, the former Hamilton striker drilled the ball into the bottom corner from 18 yards.
Motherwell manager Stuart Kettlewell brought on Vale and Jon Obika to join Theo Bair up front but the extra firepower was not evident at first.
The visitors began to look more threatening in the final 10 minutes. Bair saw a header saved and Vale curled wide before the on-loan Blackburn striker swept a low shot which went in off former Motherwell defender Darragh O’Connor.
Well could not carve out a chance to equalise as the Morton defence stood firm throughout five minutes of stoppage time.