How to handle gifts at birthday party sleepover for 8/9 year old boys?

My question is how to handle gift opening? I am afraid that if we wait til everyone has gone home the next day to open gifts the anticipation might be too much, especially for the bday boy.Also the gift giver and bday boy won't get to experience all the lessons of gift giving/receiving/thank you's etc. But if we open gifts right away I am afraid pieces may get lost, something might "accidentally" get slipped into a pocket/backpack, something might get broken and the birthday boy may see his presents being played with before he has had a chance to enjoy each item himself. How should I handle this dilemma?