Delete All Rows In Master Table If Identical In Second Table - SQL

A SELECT works:

SELECT *
from mastertable
INNER JOIN secondarytable
ON mastertable.Identicalfield = secondarytable.Identicalfield

But none of these do:

DELETE
FROM mastertable
INNER JOIN secondarytable
ON mastertable.Identicalfield = secondarytable.Identicalfield
**Incorrect syntax near the keyword 'INNER'.**

DELETE
FROM mastertable JOIN secondarytable
ON (mastertable.Identicalfield = secondarytable.Identicalfield)
**Incorrect syntax near the keyword 'JOIN'.**

DELETE
FROM mastertable
WHERE (mastertable.Identicalfield = secondarytable.Identicalfield)
**The column prefix 'secondarytable' does not match with a table name or alias name used in the query.**

DELETE
FROM mastertable
WHERE IN (SELECT *
FROM secondarytable)
**Incorrect syntax near the keyword 'IN'.**

Can anyone help? This should be easy, shouldn't it?!
Thank you.