to cap the climax
Webster's Dictionary (GCIDE)
Climax \Cli"max\, n. [L., from Gr. ? ladder, staircase, fr. ? to make to bend, to lean. See Ladder, Lean, v. i.]
1.Upward movement; steady increase; gradation; ascent. --Glanvill. [1913 Webster]
2.(Rhet.) A figure in which the parts of a sentence or paragraph are so arranged that each succeeding one rises above its predecessor in impressiveness. [1913 Webster]
"Tribulation worketh patience, patience experience, and experience hope"— a happy climax. --J. D. Forbes.[1913 Webster]
3.The highest point; the greatest degree. [1913 Webster]
We must look higher for the climax of earthly good.— I. Taylor.[1913 Webster]
To cap the climax, to surpass everything, as in excellence or in absurdity. [Colloq.] [1913 Webster]