Approval Process in Salesforce: Unlock Record BEFORE Field Update

Is it possible to ensure an approval process’s final approval/rejection unlocks the record before any of the field updates happen?

Ordinarily it seems like it doesn’t especially matter, as field updates are somehow applied despite being locked, but I am running a trigger off those field updates that attempts to delete the record, but cannot because it is still locked.

As a workaround, I’m thinking my trigger can unlock the record before deleting it, but this seems to be a senseless complication.

Surely if there are field update actions, the record has to unlock first?