Maverick filmmaker Nicholas Ray was well on his way to “Johnny Guitar,” “Rebel Without A Cause”and “Bigger than Life” when he followed up his big Bogart break “A Lonely Place” with “On Dangerous Ground,” an intense troubled cop thriller with jarring action and sentimentality mixed with sadism and masochism.

You can know film noir, be immersed in the genre, its tropes and familiar milieus, and this Robert Ryan/Ida Lupino classic will still hit you like a cold, wet slap. Beautifully composed, lit and shot by George E. Diskant (“Kansas City Confidential”), with nervous hand-held footage of chases on foot and by car, edited into three brisk and immersive acts, shot through with psycho-sexual flourishes, including Ryan at his most sadistic, it’s a black and white classic that feels so modern now it had to land with a bit of a shock in 1951.

Ryan plays ex-footballer turned hard-boiled big city cop Jim Wilson. Ray and screenwriter A.I. Bezzerides (“They Drive by Night”) did “ride alongs” with Boston P.D. and their “research” shows as the first act is one long flourish of police proceedures circa 1950 — shift briefing (led by “Captain” Ed Begley Sr.) to three-cops-in-a-car patrols, listening for tips, calls and leads on their police radio as they hunt for a couple of cop killers.

Nobody ever flashes a badge or even says “Police” as they “rough up” a man whose only crime is running in the vicinity of a robbery, make their rounds of bars and collect tips from news vendors and alcoholics.

More than one of these underworld “types” has a nervous, addict edge. And the cops? They act like everybody knows them and everybody knows they mean business as Wilson hassles a bartender for serving an underage girl, barges in on a woman (Cleo Moore) who knows somebody who knows somebody and generally throw their weight around with a kind of impunity that was supposed to have been legislated or legally ruled-out of police work in the decades since.

“Next time you hit a guy,” Wilson advises an older, sore-shouldered colleague (Charles Kemper), “don’t throw it all in one punch.”

Wilson’s so rough his partners (played by Anthony Ross and Kemper) start to question him in “job is gettin’ to you” ways.

When he corners an associate of a suspect, Wilson and his “Go on, HIT me” quarry (Richard Irving) step right up to the edge of sado-masochism in their little dance, and then cross it.

“Why do you make me do it? You know you’re gonna talk! I’m gonna make you talk! I always make you punks talk! Why do you do it? Why?”

That earns Wilson a warning that becomes a threat and evolves into a “go upstate” and pitch in on a manhunt re-assignment. A teen girl was abducted and killed. The aged sheriff (Ian Wolfe) could use the help. The furiously mistrusting father of the victim (Ward Bond at his most belligerent) is hellbent on shooting the guy when they catch him.

Wilson sees his own cop-judge-jury-executioner shortcomings in this raging father, as they are thrown together in a mad, wintry pursuit that leaves the rest of the posse behind.

That’s when they meet the blind woman (Lupino, in a subtle and vulnerable turn) who might take them in, and may be harboring the fugitive on her remote, snow-covered farm.

Ray artfully blends long takes with close-ups, fluid tracking shots with jumpy, hand-held chase sequences. Scene after scene is composed in depth, with simple actions, character traits and plot points packed into foreground and background action, with action always taking precedence over dialogue.

But the dialogue, when the picture leans on that, just sizzles.

“I like to stink myself up,” Cleo Moore’s “known associate” of a hoodlum purrs, after Wilson and his partners barge in on her and notice her vast perfume collection. She picks out a favorite. “‘Noo-it duh Joy.’ (Nuit de joie) It means ‘Night of Joy.'”

The acting pops, with hardened colleagues lecturing Wilson out of concern, and the boss, gorging himself at lunch, crossing over into stark warnings about lawsuits and a firing that could follow if this teetering-on-psychotic loner doesn’t “settle down,” in more ways than one.

Ryan handles the transition from hardboiled “Nobody likes a cop” o compassion inspired by a sympathetic and pretty woman as well as any actor of his day could have.

“On Dangerous Ground” never transcends its genre because Ray & Co. never lose track of what it’s meant to be. It sprints by until pausing for tense interludes in the third act, before barreling into a finale that it borrows from 167 Westerns that preceded it.

The whole enterprise is of a piece — soundstage interiors to backlot street scenes to chases through the snowy, remote outdoors. Future director Lupino stepped behind the camera to keep the show on the road when Ray fell ill during production and the filming and throughline of the fact-paced narrative never missed a beat.

The urgent Bernard Hermann score sounds so much like his later “North by Northwest” music that it’s hardly a shock to learn he recycled some of the instantly-recognizable incidental music from this one for that Hitchcock classic.

A “meet the screenwriter” cameo here features A.I. Bezzerides playing an owlish, greasy lowlife who offers our cruel but incorruptible cop a bribe in an early scene in a smoky bar. Ray makes great use of the character actors of the day in a film he made on the tail end of “The Studio System.” Begley, Wolfe, Bond, Olive Carrey and Frank Ferguson are among the familiar faces available to an RKO shoot in 1951.

“On Dangerous Ground” has its “wow” shots, character twists and moments. But what stands out about this early Ray gem is how surefooted Ray’s cinematic storytelling already is. It’s fluid and confident in the headlong way it plays, a noir thriller that immerses us in a world, presents its problems and sets out to solve them through a morality tale with a whiff of the creepy and the kinky about it.

Rating: approved, TV-PG

Cast: Robert Ryan, Ida Lupino, Charles Kemper, Ed Begley and Ward Bond.

Credits: Directed by Nicholas Ray, scripted byA.I. Bezzerides and Nicholas Ray, based on the novel by Gerald Butler. An RKO release on Tubi, Amazon, etc.

Running time: 1:22