This week Film Forum concludes its “NYC Noir” series with William Friedkin’s influential 1971 police procedural “The French Connection.” The sharply edited thriller pulled off a street-level peek at ball-busting cops amid urban grit — a style that’s became as much of a staple as film noir’s long shadows and doomed men of the 1940s. As Detective “Popeye” Doyle, Gene Hackman earned one of the film’s five Academy Awards, which included best picture and a well-deserved statuette for editing.

“The French Connection” is about dogged pursuit. Building his case on the run, Popeye tracks his quarry, a suave French heroin smuggler (Fernando Rey) dubbed “Frog One,” and a Brooklyn small-timer, Sal Boca (Tony Lo Bianco), who’s angling for his first big deal. Backed up by his level-headed and loyal partner, Buddy Russo (Roy Scheider), Popeye conducts stakeouts, peek-a-boo sidewalk chases, and, most famously, a breakneck race in a commandeered car versus Frog One’s henchman in an elevated N train. As if exhausted by all this, Don Ellis’s great score, which pounds over the opening credits, concludes the film with groan-like creaks.

Hung over with 24-hour police work, Mr. Friedkin’s breakthrough film was in fact inspired by a record-breaking 1961 heroin bust. Larger-than-life cop Eddie Egan, already the subject of a best-selling account by Robin Moore, advised Mr. Friedkin and even played Popeye’s supervising officer. Like Popeye, Egan’s investigation zeroed in on a heroin-packed car imported with the aid of a French entertainer. (The real-life figure, Jacques Angelvin, was convicted, and later penned a travel guide about his prison stays called “My American Prisons.”)

Mr. Friedkin, who directed two adventuresome crime documentaries in the 1960s (“The Thin Blue Line” and “People vs. Paul Crump”), grounds the sweat and dirt of Popeye’s investigation in New York concrete. The opening chase sends Popeye, in a Santa Claus suit, galumphing down a Harlem sidewalk and cornering a hood in an abandoned lot. He stalks Frog One outside genteel Madison Avenue shop-fronts, but goes home to an institutional Brooklyn project. A clandestine car tail to Randall’s Island is stymied by a gloriously mundane traffic jam, raucous with horns. The versatile Mr. Hackman had already notched two Oscar nominations, for “Bonnie and Clyde” and “I Never Sang for My Father,” but “The French Connection” was nevertheless a milestone, high-profile and top-notch. He’s the movie’s alert center, the scrappy, gleeful, profane embodiment of the city. Knocking heads, busting shoe leather, Popeye is impishly charming in his rumpled tie and pork pie hat, though an inveterate skirt-chaser (go-go boots, actually) and a casual slur-hurler.

Mr. Friedkin keeps the camera-work robust and mobile to catch up with Popeye (and is smart enough to let editor Jerry Greenberg keep scenes taut). The ins and outs of the surveillance come trickily alive through nimbly handled long shots. Watch when Popeye and company track Sal Boca through Midtown: Our view trapezes from one person to the next with impossibly timed roving pans, before a cut and a tweak bring the background, and the target, back into focus.

“The French Connection” hits the sweet spot of urban grit, perhaps by virtue of its early entry in the grimy ’70s sweepstakes. This New York is indeed broken-in, featuring a magnificently dilapidated warehouse, but it doesn’t wallow, stagger, and vomit like the squalid and bankrupt Gotham of Martin Scorsese’s 1976 milestone “Taxi Driver.” Nor does Popeye’s dispute with a federal agent attached to the case carry grimly satisfying anti-establishment overtones. Perhaps screenwriter Ernest Tidyman split the difference between his work on the glam attitude of “Shaft” (which made its debut the same year) and later in the deep-cover flick “Report to the Commissioner.”

Mr. Friedkin has enjoyed a brief return to the spotlight thanks to the trifecta of his recent paranoia chamber piece “Bug” (released in May), and the revivals of “French Connection” and his controversial 1980 gay-underworld thriller “Cruising,” which starts at Film Forum next week. After the adventures of Popeye, he followed up with the sinfully profitable excesses of “The Exorcist,” but “The French Connection” remains the pinnacle for wholesome heroin-bust entertainment.

Through September 6 (209 W. Houston St., between Sixth Avenue and Varick Street, 212-727-8110).