sql delete records based on combination of multiple fields in other table I need suggestions on deleting records in relation with another table

Main Table:

c1 c2 c3
2  5  3
1  2  8
1  2  NULL
1  4  7
2  4  8
1  3  NULL
2  5  NULL
5  1  3
1  5  1


I need to delete all rows where c1 and c2 are identical to a row where c3 is NULL.

e.g.: for c3 is NULL if record c1=1 and c2=2 delete that record as well as c1=1, c2=2 and  c3=8

The resulting table should be

Main Table:

c1 c2 c3
1  4  7
2  4  8
5  1  3
1  5  1
DELETE t1
FROM Table t
    JOIN Table t1 ON t1.c1 = t.c1
        AND t1.c2 = t.c2
WHERE t.c3 IS null