Deleting rows from a tag_map if parent tag exists

Question

I have a simple tag_map

CREATE TABLE tag_map
(
article_id int(11) unsigned NOT NULL,
tag_id int(11) unsigned NOT NULL,
INDEX(tag_id),
PRIMARY KEY(article_id,tag_id)
) ENGINE=InnoDB

There is a table for interlinking the tags (some are parents of the other)

CREATE TABLE tag_parents
(
tag_id int(11) unsigned NOT NULL,
parent_id int(11) unsigned NOT NULL,
INDEX(parent_id),
PRIMARY KEY(tag_id,parent_id)
) ENGINE=InnoDB

I want to delete any row from tag_map if there is a link with the parent of that tag.

For example,

article_id    tag_id
1             1
1             2
1             3
2             3

tag_id      parent_id
3           2
1           1

I need to delete any article with tag_id 3 if it is already linked to its parent tag_id 2.

Output:

article_id    tag_id
1             1
2             3

I thought of

DELETE a FROM tag_map a 
    JOIN tag_map b ON a.article_id=b.article_id 
    JOIN tag_parents c ON a.tag_id=c.tag_id AND b.tag_id=c.parent_id

Since these are huge tables, I look for a better query in terms of performance.