"Don't let the bastards grind you down," is the message in this belligerent portrait of working class manhood, adapted from the 50s novel by Alan Sillitoe.
Following defiant factory worker Arthur Seaton (Finney), "Saturday Night and Sunday Morning" offers a terrifying glimpse into an age where work, booze, and death were all that Britain's young men had to look forward to.
Set in Nottingham at the end of the 50s, "Saturday Night..." offered newcomer Finney the chance to really show what he could do on-screen.
The result is a smouldering, poison pen letter of a film in which Finney's working class hero - a rarity in the stuffy days of postwar British cinema - battles the system with a near-religious fervour.
"What I want is a good time, the rest is all propaganda," is Seaton's mantra, but in the end, he realizes he's fighting a losing battle as an affair with his best friend's wife (Roberts) ends badly, and his aggressive attitude alienates him from everyone.
Finney exhibits a talent and screen-presence here that helped make him a star. Meanwhile, director Reisz (who went on to make "The French Lieutenant's Wife" in 1981) stays faithful to the spirit of Sillitoe's novel, never compromising on either the bleakness of his vision or his (over) optimistic faith in his hero's defiance.
It ends on an ambiguous note of stone-throwing anger, leaving you wondering if Finney's independent spirit might yet save the day... or be squashed into passive middle age on the housing estate he loathes.
A fascinating film, and a snapshot of an era that's depressingly all too real.
"Saturday Night and Sunday Morning" is reissued as part of the British New Wave season at London's Barbican Centre on Friday 11th October 2002. "The Loneliness of the Long Distance Runner" and "A Taste of Honey" are also being shown.