“Rebel Ridge” opens with a shot of a lanky, muscular stranger riding into a small, corrupt Southern town — a scene we’ve all seen plenty of times. Except this stranger isn’t in a truck or on a horse. He’s on a bicycle.

It’s one of many ways that writer-director Jeremy Saulnier both honors and has fun with movie conventions on his way to making clearly one of the best things on Netflix.

The tight, taut and tension-filled “Rebel Ridge” is the story of a former Marine who arrives in Shelby Springs, Louisiana, to post his cousin’s bond and gets sucked into taking on its shady law enforcement department.

The last time a relative came to help his cousin from the clutches of less-than-ideal small town Southern legal system it was a comedy with Joe Pesci and a hero named Vinny. If you ever needed a hint that this isn’t that movie, the opening sequence is scored to Iron Maiden.

The movie stars Aaron Pierre as our former Marine, Terry Richmond, a man with mad martial arts and survival skills (he catches fish with his bare hands), and, on the opposite side, Don Johnson as the courtly but deadly chief of police, as venal as Richmond is noble. Both seem absolutely to adore their gun-slinging, testosterone-filled roles.

Saulnier — who dealt with frontier justice and lawlessness in his previous “Blue Ruin” and “Green Room” — has given this action-thriller loads of social context: racism, opioid addiction, the cash bail system, small-town funding and militarized cops.

Like its leading man, “Rebel Ridge” is a lean, muscular movie with few over-the-top special effects, save for Pierre’s spectacular eyes. It’s a triumph of small-budget, naturalistic filmmaking, where cars on a gravel road kick up choking clouds of dust and arm bones crack when pressure is applied.

The script is spare — allowing for some homespun poetry like “You know the thing about a pissing contest? Everybody gets piss on their boots” — and without an ounce of fat. So if a bottle of coconut water is brought up in one scene, it’s going be used in another. There are interesting camera angles, like the backseat of a speeding car or a tense cell phone call inside an old-fashioned phone booth.

There’s also great use of dramatic underscoring by Brooke and Will Blair, who build discordant waves that grow slack, only to reappear like a shark. The score — including “Wayfaring Stranger” by Neko Case or “Right Brigade” by Bad Brains — are heard only on car radios or headphones or playing in restaurants. Distant thunder sounds often.

Our ex-Marine — described by one officer as “unarmed but considered dangerous” — forges an unlikely ally in a court clerk, played winningly by AnnaSophia Robb, and there’s a plumb role for James Cromwell, too.

“Rebel Ridge” has whiffs of all kinds of other movies, from “First Blood” to spaghetti Westerns, while the script even humanizes the bad guys — “Just because you was right doesn’t make us wrong,” the chief says to our hero.

There’s a conspiracy at the heart of the town and you likely won’t be able to turn off the movie before finding out if one well-trained stranger can save the day, as things gloriously escalate. “It’s gotten out of hand. Real soup sandwich,” says our hero. That’s not what ended up on your TV screen, though — it’s the very opposite of a mess.

“Rebel Ridge,” a Netflix release that begins streaming on Friday, is rated TV-MA for “language, smoking and violence.” Running time: 131 minutes. Three and half stars out of four.