Green’s Dictionary of Slang

first rate, overwhelming, usu. of a performance.

1923		Variety 11 Oct. 16 [headline] ‘Rosie O’Reilly’ and ‘The Fool’, Loop’s Two Smash Hits.
1929		J. Lait Broadway Melody 36: The girls whom he must imbue with the tempo and spirit of his smash song.
1952		W. Winchell On Broadway 5 Sept. [synd. col.] Patti Page, happy about her newest smash recording.
1975		Sun. Times Mag. 12 Oct. 64: Her first boyfriend Neil Sedaka had titled his smash hit Oh, Carol.
1976		P. Theroux Family Arsenal 44: Naturally it’s a smash-hit, it’s always full.
2000		Indep. Rev. 23 Feb. 3: His TV smash-hit comedy One Man and His Dog.