Morton won their third Ladbrokes Championship match in a row as Denny Johnstone's early penalty was enough to hand them a 1-0 victory against Livingston at Cappielow Park.Morton took the lead after six minutes when defender Conor Pepper was brought down by Jackson Longridge and referee Craig Charleston pointed to the spot.Johnstone sent Livingston keeper Marc McCallum the wrong way to bury his spot kick in the net.Liam Buchanan spurned a fine chance to draw Livingston level on the half-hour mark as he curled Scott Pittman's cut-back pass just over. Shortly after the restart Jordan White rose highest to head Gary Glen's floated corner goalwards but home keeper Grant Adam was relieved to see the ball just clear the crossbar.Livingston substitute Jordyn Sheerin wasted a decent chance to draw Livingston level midway through the second period but he shot wide as the angle narrowed and Morton held on for all three points.