Only return one entry if column "X" value isn't unique?

I have a "progress" table, which contains, amongst others, a "course_id" column.

I want my call to return only one entry per unique "course_id" value.

For example, if I have these entries in my "progress" table:

id="1", title="bla", course_id="1"
id="2", title="blabla", course_id="1"
id="3", title="blablabla", course_id="2"

The call should return items "2" and "3", because entries "1" and "2" have the same "course_id" value, and "2" is the max of them both.

Any help greatly appreciated.