“Rye Lane” has all the ingredients of a classic romantic comedy. All of them.

It starts with a “meet cute,” introduces a morose, just-dumped guy to a Manic Pixie Dream Girl, compresses time into (mostly) a magical single day walking-and-talking “date” through a colorful corner of the world, hits all the comically wrong notes in karaoke moment and finishes with a Grand Romantic Gesture.

First-time feature director Raine Allen Miller and writers Nathan Bryon and Tom Melia immerse us in Brixton, South London. And they and their stars Vivian Oparah and David Jonsson upend a few rom-com conventions and improve on a few others in the most delightfully charming screen romance in ages.

The “meet cute” is in a public toilet, with the camera tracking over the tops of the various stalls to zero in on weepy Dom in his pink Converse and Beats, and brassy stranger Yas trying to comfort him from from the next “unisex” stall.

She’s a Manic Pixie Black London Girl, and apparently determined to press this “random” for details of his “mess.”

“EVERYBODY has a mess,” she reassures him.

And over the course of a day, walking the crowded, colorful streets, watching OAPs (old age pensioners) learning tai chi in a park, eating street food and extending the day with an “Oh, I’m going this way too” every so often, we flash back to his messy breakup, and even get around to hers.

It’s like The Beatles’ “Penny Lane” as a rom-com. It’s all cute and charming and “real,” and bloody adorable.

Allen handles every flashback to this “sign” (red flag) that things weren’t going well in the previous relationship, or that red letter date when it was officially “over” differently. There are quick, literal recreations and longer, comically-idealized “I WISH it had happened this way” takes.

One even has Yas acting out her theatrical break-up on stage in front of a theater packed with Doms.

But he’s an accountant, shorthand for “boring” even if you’re Black, even in the UK. And she’s an aspiring costume designer, hoping for a big break, shorthand for bubbly, upbeat and force of nature. Can this go anywhere?

We’ve seen scores of other versions of her impose-herself-on-his “first time seeing my ex with my ex-best friend, who cheated on me” meet-up. Oparah turns it into a hilarious napalming of the beautiful but faithless ex (Karene Parker) and the dopey, handsome lout (Benjamin Sarpong-Broni) she preferred to Dom.

The set-up is a cliche, the characters reduced to “types,” and playing the hell out of it makes it a spit-take riot.

I loved the way the film peels away layers of hurt for each character, inverts their roles as Dom — in time-honored Manic Pixie Dream Girl rom-com style — becomes the bubbly, outgoing one for a bit and Yas becomes the passive, quiet one, reliving old pain.

But Oparah was born to be this brash, her every bit of banter worth watching with subtitles so that every bite of Cockney-Creole slang can be savored.

“He was tryin’ to DILUTE my squash, and I was like ‘NOT TODAY, Satan!'”

There are hijinks to be had, a Jamaican backyard cookout to be crashed, confrontations to come and wisdom to be shared, most of it from the lady who is sure “EVERYbody has a mess!”

“There are two types of people in the world, the ones who wave (back at people waving at them from) boats, and people who hate joy!”

And then, a “Wait, WHAT?” cameo pops up, a random moment in a movie built on them that rivals media philosopher Marshall McLuhan’s appearance in “Annie Hall.”

Let’s just say there’s a burrito shop worth stopping by on their walk. It’s called “Love Guac’tually.” And the grizzled burrito maker would make Jane Austen spit out her Fanta.

This Sundance darling would have been a perfect Valentine’s Day date-movie release. But that would’ve been rushing things. Searchlight/Disney have their hands on one of the best rom-coms in years, and it may take a while to build buzz for it.

So here’s that buzz. The film opens March 31. Remember it, make a note. And wait for that cameo. It’s a hoot, and one among many in this slice of romantic life along “Rye Lane.”

Rating: R, sexual situations, profanity, toilet humor

Cast: David Jonsson, Vivian Oparah, Karene Parker, Poppy Allen-Quarmby, Benjamin Sarpong-Broni and Simon Manyonda

Credits: Directed by Raine Allen Miller, scripted by Nathan Bryon and Tom Melia. A Searchlight release.

Running time: 1:22