The draw means the top of the table positions stay the same, with Plympton still leading, but second-placed Saltash are just three points behind with a game in hand.
The sides will meet again at the start of May – a match which is likely to decide who finishes as champions.
Saltash started well on Sunday and hit the woodwork after less than 90 seconds, but it was actually Plympton who took the lead when Isabelle Firth got down the right and fired a low shot into the net.
Nicola Champion had a great chance at the other end just minutes later but was just wide with her effort.
However, she did pull her side level in the 35th minute when a goal-kick fell to her and she ran it back and beat the goalkeeper.
Plympton had a good chance when Firth broke the offside trap in injury-time, but the Saltash goalkeeper came out and fouled the attacker outside the box. The referee awarded the freekick, but did not produce a card for the goalkeeper.
At the other end, the Plympton goalkeeper also had to make a good stop before the break.
Saltash increased their lead seven minutes after half-time with a goal from Liv Lennox.
In the Devon League South & West Division, SB Oak Villa continued their good form with a 4-1 home victory over second-placed Elm United.
It was Oak Villa’s fifth league win in a row and came courtesy of goals from Mia Dulling 2, Natasha Shekhdar and Saskia Brisley. The victory has moved Oak Villa up to fourth.
Elsewhere in that division, a goal by Angel Goucher secured Lakeside Athletic a 1-0 away victory at ever-improving Tavistock.
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