Been there, done that. In all my many years of observation, including putting up shows or events, I only follow one rule---whether it's an ordinary public speaking occasion, a party, or any show for that matter, how the event starts determines the ending of the affair. I always follow the rule of "dropping the bomb" at the very start or giving the audience a mesmerizing opening and everything will be all right.
I recently attended a grand birthday party---grand in the sense that the venue was perfect, food was excellent, and the clothes and costumes of the performers were top rate, but I couldn't help yawning even at the very start of the show. The event planner seemed to have reserved the best part at the very last which, to me, came out too late the hero as I already was too damned tired to appreciate anything, not even the dropping of a bomb at the end could have saved me from boredom.
I guess it isn't too much to ask from party planners to start the party with the best part.