ARGYLE'S defensive problems continued as this heavy defeat at the hands of local rivals made it 13 goals conceded in their first five EFL Youth Alliance fixtures.
Torrential rain, just prior to kick-off, made it a slippery surface at Tavistock's Crowndale pitches but that was not an excuse for Argyle's poor defending as they found themselves three goals down inside the first 19 minutes.
Rubin Wilson hit a first-time shot wide in the second minute but that was the last seen of the Argyle attack for the next half-hour as the young Grecians ran the show. Cheick Diabate was left totally unmarked at the far post, only for Tyler Coombes to make a fine close-range save.
It was only a short reprieve for the Greens as Harry Ford's driven cross hit Reuben Collum to give Exeter skipper Louis Morwas the chance to give the Grecians an 11th-minute lead from the penalty spot.
Exeter struck again, a minute later, as Nelson Iseguan was left free at the far post to fire back across goal and inside the far post. Coombes denied Iseguan with another fine save but the Argyle defence was once again missing as Diabate steered a free-kick home from close range.
Iseguan was once again foiled by Coombes before Argyle had the second attempt of the half when Wilson held the ball up well but Rhys Shirley his shot wide from the edge of the box.
The home defence did not improve after the break as Exeter made it 4-0 on 59 minutes, as a mix-up between Ali Mansaray and Ollie Tomlinson ended with Harry Ford firing low into the corner from the edge of the box.
Coombes then denied Ford a second before good play by Mani Skett saw his cross fired wide, at the far post, by Alfie Wotton. Substitute Oscar Massey then had Argyle's best attempt of the game as his low drive flew narrowly wide from 20 yards.
The scoring was completed on 78 minutes as the ball came back off the crossbar for Frank Lovet to convert the loose ball. Argyle's misery was completed when Mansaray collected two cautions in as many minutes to leave his side seeing out the last five minutes with 10 men.
Argyle: Tyler Coombes, Ali Mansaray, Brandon Pursall, Jarvis Cleal, Ollie Tomlinson, Jude Boyd, Mani Skett, Alfie Wotton, Rubin Wilson, Rhys Shirley, Reuben Collum (Oscar Massey h-t). Substitutes (not used): Carlo Garside, Harry Townsend, Matt Bartlett, Will Jenkins-Davies.