PARK CITY REPORT : The Standouts at Sundance--Kensit, Vasquez : Movies: The actress’s performance in ‘Twenty-One’ is the town’s unqualified hit. The writer-director’s ‘Hangin’ With the Homeboys’ is in the best tradition of this independent-driven film festival.

The Sundance Film Festival has changed the course of more than one filmmaker or actor’s life. Ask Steven Soderbergh or any of his “sex, lies, and videotape” stars Andie MacDowell, James Spader and Laura San Giacomo. Or, ask Reginald and Warrington Hudlin, whose genial Sundance hit “House Party” helped land the brothers a deal at Tri-Star Pictures.

Only half-way through this year’s festival, Sundance can claim two more discoveries: 22-year-old actress Patsy Kensit, whose performance in director Don Boyd’s “Twenty-One” is the town’s unqualified hit; and 27-year-old writer-director Joseph B. Vasquez, whose “Hangin’ With the Homeboys” is in the best tradition of this independent-driven festival.

London-born Kensit, whom most people know from her role opposite Mel Gibson in “Lethal Weapon 2,” may gain from “Twenty-One” what Julie Christie gained 25 years ago from “Darling”--international stardom. On hearing that comparison, over breakfast with Boyd in a Park City restaurant, the green-eyed, fresh-faced Kensit glows. “Julie Christie’s always managed to retain her Englishness, hasn’t she?,” she says.

Although “Twenty-One” and “Darling” are told differently, the central roles have certain similarities. Christie’s Bird in “Darling” was a blithely amoral beauty in swinging London who took life on her terms, snapping hearts like pretzel sticks. As “Twenty-One’s” narrative moves between London and New York, Kensit’s Katie--who confides to the camera in monologues that have the intimacy of a teen-ager writing in her diary--cuts a pretty wide swath as well. It’s an amorous history that begins with her liaison with a friend’s bridegroom moments after the wedding, and goes on through Bobby, a handsome, self-destructive Scot whom Katie fancies she cannot live without.

“Even I was a bit shocked by some of Katie’s behavior,” Kensit said thoughtfully, “but I loved the idea that I wasn’t anyone’s girlfriend, and I had all the men. And when she gets into that relationship with Bobby, your heart melts. We always love the wrong people, don’t we?”

“I wanted to avoid her being saccharine-based,” said Boyd, 42, who co-wrote the screenplay with 24-year-old Zoe Heller, whose previous experience had been as a British literary critic. “ ‘At the very least,’ I used to tell Patsy: ‘People are going to be interested in you.’ ”

It isn’t simply Katie’s astonishing openness that makes her so memorable. It’s Kensit’s innate appeal--her sweet-and-sour mixture of brass and tenderness--that humanizes Katie’s every move.

“When we were doing the movie,” Kensit said, “I was going through a lot of personal pain. I had just split with my husband. But the whole point of the movie is about losing someone, so it was a very cleansing thing . . . I don’t think I could have given that performance if I hadn’t felt a loss like that myself.”

Raised by a non-theatrical family near the leafy London suburb of Twickenham, Kensit’s debut at the age of 4 as Mia Farrow’s daughter in “The Great Gatsby” was a fluke. The casting agent, instructed to find director Jack Clayton a non-professional child, turned to her friends’ youngsters, and Kensit got the job. After that, the convent-schooled girl studied acting at every summer break, eventually working on everything from the ill-starred production of “The Blue Bird” in 1976, to television performances with the Royal Shakespeare Company. There was even a detour at 14, when Kensit sang lead for her brother’s pop group, Eighth Wonder, an act that suggests an extremely understanding family.

“The best thing my mother’s gotten from me,” Kensit said with a laugh, “is that I’m very down to earth about the business of my career. It’s all an adventure, really. I look on every movie as being the last. I can’t quite believe all this now.”

If her film roles have been secondary--besides the South African embassy secretary in “Lethal Weapon 2,” audiences may remember Kensit as Crepe Suzette in Julian Temple’s “Absolute Beginners”--her tour de force performance in “Twenty-One” may signal the end of such talent-wasting. Boyd suspects as much and worries about the pressure she will soon face.

“I’ve been trying to persuade Patsy to resist falling into a mainstream career,” Boyd said, “one that would destroy the opportunity to create any number of European films revolving around the talents of an extraordinary actress.”

The pungent, insightful “Hangin’ With the Homeboys” is the third feature by Bronx-born Vasquez, a writer-director with style and compassion in equal amounts. “Homeboys’ ” seriocomic story is hung from a not-unusual-peg, the all-night adventures of a quartet of close buddies, in this case from the Bronx.

Where it veers away from the competition is in Vasquez’s skill in characterizing each one of the four, in revealing their delicate shifts of allegiance and in suggesting their future--hopeful or otherwise. All this within the framework of a movie whose dialogue is salty and real enough to crack up the homeboys themselves.

It’s hard to keep your cool when an audience gives your film the tumultuous appreciation that “Homeboys” got Sunday afternoon. Vasquez finally gave up trying; his delight radiated through the house. His aim, he said, was “Just gettin’ people to see the love I had for these guys,” each of whom he had been at one stage of his own life: innocent, nerdy, cocky, chauvinistic, hesitant, love-struck, ambitious.

The next day, his enthusiasms barely dampened by a cold, he elaborated. Bronx-raised with his two brothers by his grandmother, Bertha, he’d gotten his hands on his first camera at age 12.

He shot whenever he could, making at first his own “Superfly,” his own “Rocky,” his own “Exorcist.” Next came study at the City College of New York, followed by intensive work as a film editor. With the savings from that job, he made two low-budget films (“Really low budget . . . like $30,000,” he said).

Vasquez moved from the Bronx to Manhattan’s 77th Street where he learned firsthand about Manhattan’s much higher prices. In a bind to keep up with his rent, he locked himself in his room for three days and came up with the screenplay.

“I’m either very brilliant or bugs,” he suggested.

He took his script to New Line’s Janet Grillo, who was a fan of his two early movies, and the two worked together to smooth out its raw edges. Then, with a budget of less than $2 million and only 30 days in which to make it, Vasquez began shooting.

Three weeks into the schedule, Vasquez was attacked on a subway train and it required 50 stitches to close the cuts on his face. Ironically, it was the only act of violence related to the project; there is none in the film.