Denny Johnstone netted a first-half brace as Morton returned to winning ways with a 3-2 victory over Queen of the South at Cappielow Park on Tuesday night.The hosts got off to a strong start as Declan McManus set up on-loan striker Johnstone for a close-range tap-in eight minutes in.The 21-year-old on-loan Birmingham forward added a second for the Ton midway through the first half as he slotted Bobby Barr's cross into the bottom corner for his 14th goal of the season.Paul McMullan made it three after finding the bottom-right corner of Robbie Thomson's net following successive failed attempts to pull one back from Gary Oliver either side of Alex Harris' saved effort down at the other end.The Doonhammers almost took the lead on the hour mark as they tried to come back but Callum Tapping's long-range shot was saved before Dale Hilson did pull one back for the visitors, firing Harris' cross home from the centre of the box with 20 minutes remaining.Oliver had a chance blocked but made sure he found the net moments later as the former Hearts youth player picked out the top-right corner to make it 3-2 with 12 minutes remaining but Morton held on for all three points to move into fifth.