top of the hour

amateur hour

A situation or activity in which the participants show a lack of skill, sound judgment, or professionalism.

cherry on top

Synonym of icing on the cake (“a thing which intensifies the appreciation of something already good, or (ironic) the regretting of something already bad”).

eleventh-hour

Just before the moment that it is too late; in the nick of time; last-minute.

finest hour

A point in time or a relatively brief period of time when an especially distinguished, admirable, or effective set of actions is performed.

long hour

Any of the late hours of the day, especially those nearing midnight, or the hours after sunset.

on top

In a dominant position.

over the top

Beyond normal, expected, or reasonable limits; outrageous.

put the bottom rail on top

To reverse a hierarchy.