Elliott Frear claimed a hat-trick in the opening half-hour as last year’s runners-up started their domestic campaign with an emphatic triumph at Fir Park in the Group G clash.
The League Two visitors, who had claimed a bonus point after drawing with Clyde at the weekend, looked well off the pace and were five goals down by half-time following Frear’s treble and single strikes from Richard Tait and Curtis Main.
The sides met in the group stage last season, when Edinburgh City gave the Steelmen a fright after taking the lead, but that never looked likely to happen this time around.
The hosts started brightly, dominating possession and pressing high up the pitch and it did not take long for Frear to break the deadlock. The impressive Chris Cadden fizzed a low ball across the six-yard box and the winger tapped in at the far post.
The lead was doubled ten minutes later as Tait won the ball back on the edge of the box and fired a low shot past Calum Antell, before Frear curled in a delightful second to put the hosts 3-0 up inside 25 minutes.
The winger had his hat-trick three minutes later, exchanging passes with Cadden on the edge of the area before opening his body up to curl into the far corner and well beyond Antell.
Cadden was denied by the bar soon after but the fifth goal did arrive for Motherwell just before the break, Main getting in on the act with a well-struck drive from outside the area.
The pace slowed down after the interval as Motherwell manager Stephen Robinson brought on Alex Rodriguez, Conor Sammon and Danny Johnson to join Liam Donnelly and Mark Gillespie in making their debuts for the club.
The game fizzled out with the hosts happy to settle for a 5-0 win despite barely mustering a shot at goal in the second half.