Help with JOIN query

I can't see how to accomplish what I need so if anyone has any suggestions they would be gratefully received... I'm using mysql 4.0.20 by the way. I have two tables : TableA record_id product_ref TableB timestamp record_id action I want to create a SELECT that joins these 2 tables where the JOIN to TableB only returns the most recent entry by timestamp. At present (using PHP) I do a SELECT on TableA then for each record returned I perform a 2nd SELECT something like : "SELECT timestamp, action FROM TableB WHERE record_id = '$record_id' ORDER BY timestamp DESC LIMIT 1" I now want to do it with one query to enable sorting the results by 'action' from TableB. Any suggestions? Hopefully I've made sense, if not I'll happily try and explain further on request. -- Graham