A Ryan Wrestren hat-trick was not enough to stop Launceston being relegated to National Two South after losing to Blackheath.
The hosts went behind early to scores from David Allen but Wrestren ran in a superb try to get Launceston moving.
He added a second and Lewis Webb pushed over the third before Tyson Lewis and Lewis Webb then struck back for Blackheath.
Wrestren and Lewitt both crossed again but three further tries cemented Launceston's fate.
Jack Walsh, Ed Doe and Allen all crossed the line with the hosts down to just 14 men after winger Ben Turner's late challenge on Jack Walsh.
But Launceston's fifth try in the dying minutes of the match, courtesy of Kieran Lewitt, was not enough to claw back Blackheath's advantage.