Launceston coach Tony Rocques blamed poor tackling for his side's 33-30 loss at Shelford in National Two South.
Feofaaki Lea scored two first half tries for Shelford while Tim Mathias and Kieron Lewitt scored for Launceston to make it 20-18 at the break.
Lewitt got a second just before Ben Hilton scored to give Launceston a 30-26 lead, but a 71st minute try from Taniela Bakoso won it for Shelford.
"It goes down to missed tackles," Rocques told BBC Radio Cornwall.
"Once you give players time and space to run they look a million dollars, but when we made our tackles they didn't look that great," he added.