The problem with that approach is that you still get a delay due to the portal filter having to be evaluated for each related record in order to determine which record will appear in the portal.
How about not using any portals?
In Manage | Database | relationships, you can double click a relationship line to specify a sort order for the related table. If you can specify a sort order that makes the most recent record the first related record--such as sorting on an auto-entered serial number, date or timestamp field in descending order, then you can simply put the fields from your portal directly on your layout with not portal used at all.
Sorry i was lying.
I need the most recent record when field1 = "Yes"
Is this something i can also sort and filter via relationship?