When I was a kid thrashing away at tennis lessons, I never could have imagined that, had I stuck with the sport (and, y’know, been good at it), it could have one day led to something like the sexy entanglements of Luca Guadagnino’s Challengers (in theaters April 26). Who knew that a game of such lonely focus could actually be the conduit for charged, erotic interpersonal adventure?

Challengers, written by Justin Kuritzkes, is something of a souped-up fantasy in which the rigorous work of being a professional athlete is, at nearly every turn, amiably offset by a languid air of summery possibility. There is grit and anger and all kinds of professional envy, sure. But that tension is easily broken by a snappy conversation, by a witty bit of flirting.  These elite, hard-driving machines are also having a lot of fun. And thus, so do we.

For a while, anyway. The film jumps around in time, using a fraught 2016 tennis match between top-of-his-field star Art (Mike Faist) and down-on-his-luck Patrick (Josh O’Connor) as its framing device. This is a podunk tournament in New Rochelle, but the stakes seem awfully high for these two men. Challengers then travels back to the opponents’ younger days to explain why this all means so much. Art and Patrick’s teenage and collegiate years are the movie at its most alluring, a heady cocktail of sex and showmanship and nascent movie-star glow that feels awfully special and rare in this era of wan and featureless pop cinema.

Art and Patrick are childhood friends, having boarded together at a prestigious tennis academy. In the mid-aughts, they are about to graduate and head to college (for Art) or go pro (for Patrick) and are competing as a doubles pair in the juniors competition at the US Open. It’s there that they lay eyes on Tashi (Zendaya), a true phenom prodigy who is on her way to mega stardom. The boys chat her up at a party and do a good enough job of winning her over, despite their goofy fumbling, that she agrees to continue their evening. In a smoky, beer-can-littered hotel room, the trois become a menage.

Or something close to it. Guadanigno stages this seduction scene (in which there is never any doubt that Tashi is in charge) with giddy, homoerotic (or is it panerotic?) verve. Things are loose and playful but also, throbbing beneath the surface, quite serious, too. We are witnessing the crucial pivot point of a friendship; it would probably be better for everyone to stop, to not complicate things in this way. But the rational mind is no longer in the driver’s seat. Tashi is interested in these boys for herself, but she is also prodding at them, egging them on to see what they actually might mean to one another. Is all their competitive bonhomie, that intense school-chum bond, masking a simpler attraction?

That question is batted at throughout the film, but Tashi remains the main object of the men’s obsession. The triangle of Challengers is ever realigning; as the years tumble on, Art and Patrick swap advantage, in love and career. What gets lost a little in that shuffle is Tashi, whose dreams are derailed by an injury and who gradually becomes a tally mark on Art and Patrick’s scoreboard. Granted, she is the most important tally mark—but Challengers nonetheless turns a formidable character into something of an object by the end.

Challengers isn’t exactly “bros before hoes.” It’s too humane and sophisticated a film for that. But it would have been nice to see Tashi develop alongside the two men so hungrily in her orbit. Zendaya, Faist, and O’Connor have a deep and magnetic rapport—tender, turned-on, biting—that the film deftly cultivates in its first hour. If only the second half, as Challengers turns harder and meaner, gave it the same care. Instead, the back-and-forth of the romantic melodrama grows repetitive, a rally that goes on too long.

At least the tennis stays exciting. Guadagnino films the gameplay so kinetically and legibly that every thwock of the ball, every bead of sweat is felt. The sport is depicted as a lovely brutality, hard and straining but a glorious whole-body experience. Speaking of bodies, Guadagnino certainly knows how to film those of men, resting and in motion. The camera glides over Art and Patrick, or pauses to consider them, in a manner that feels more celebratory than it is leering—a lusty awe for chests and thighs and jawlines that is almost sweet in its appreciation.

The movie’s approach to semi-taboo desire is generally guided by a disarming kindness, a vicarious and earnest excitement for the potential of these people’s lives, channeled through the language of sex. The undulations of these relationships, volleying from gentle to ferocious, is perhaps best illustrated by Trent Reznor and Atticus Ross’s mesmerizing score, a swooning blend of electronic pulse and lilting piano.

Challengers is a fascinating art-house tweak on a conventional sports movie, a Bull Durham made by a gay Italian with a flair for the dramatic and offbeat. It is a true star vehicle that asserts Faist and O’Connor as new leading men and gives further dimension to Zendaya’s already well-established profile. The humble ambition here is to charm and entertain, to arouse and amuse. This is, in that way, a refreshingly sincere and uncynical movie. Challengers may tire toward the end, but it’s scored enough points by then that a few double faults probably don’t matter. How cool it seems to be young and hot and really good at something—whether that’s playing tennis or starring in movies.