The victory at Manadon moves the young Greens up to second in the South West League Western Division.
Argyle scored two goals in each half, with Wensday Wise getting them off the mark in the opening minute before Rosie Shipp scored on 15 minutes.
Wise added a second in the 70th minute before Panagiota Papaioannou completed the scoring three minutes from time.
In the South West League Premier Division, Marine Academy Plymouth pushed unbeaten Torquay United hard at Ivybridge before narrowly losing 3-2.
In a tight, physical encounter, Beth Crocker and Samantha Drewery scored for Marine.
In the Devon League Western Division, Signal Box Oak Villa were beaten 3-1 by Torquay United’s second team.
Victoria Moreton scored Signal Box’s only goal, with Harriet Bowring, Antonia Nash and Leanne Robins netting for the visitors.
In Cornwall League Division One, there was a great match between neighbours Saltash Borough and Saltash United Development at Kimberly Stadium on Sunday.
Borough won 4-3 but the game could have gone either way with United having two goals disallowed.
Both sides scored in the first 10 minutes with the experienced Kirsty Lambert putting United ahead before Lucy Borthwick replied.
Abby Shapland then gave Borough the lead in first-half injury-time.
Borough looked to have made the game safe with two goals in 16 minutes from Sam Metters midway through the half, but United finished strongly.
After having a goal ruled out for off-side, Finch pulled it back 4-3 with a penalty in the 86th minute. The Ashes then threw everything at their neighbours in the dying minutes trying to snatch an equaliser.
Borough, though, were able to hang on for their first win of the season. However, it did come at a cost with Hollie Congo suffering torn ankle ligaments and a suspected broken metatarsal.
Saltash United’s first team should have been playing Halwill in the FA Women’s Cup second qualifying round but the game was postponed due to Covid issues in the Halwill camp.
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