Morrish clocked 38 minutes and 12 seconds for the tough multi-terrain event, which involved a number of water crossings, around Radford Park.
He was pushed hard by Plymouth Harriers’ Steve Hill and Neil Myton, who finished second and third.
Hill, first over-40 athlete home, clocked 38.37 minutes and Myton 38.49.
Jay Morton (40.42) was fourth and Erme Valley Harriers’ Michael Miners (40.46) fifth.
Maddie Horton was first women in 41.12 minutes. Erme Valley’s Sarah Hirons was second in 44.07 and Tavistock’s Sam Lake third.
More than 150 athletes finished the race, which started and finished at Oreston Academy.
Full results can be found HERE