Starring Jarkko Lahti. In Finnish, with English subtitles. Rating unavailable

Don’t cue the Rocky theme for The Happiest Day in the Life of Olli Mäki, a sublimely realized true story about the rigorous exercise of one athlete’s soul. In fact, the only off-screen music here is a twangy surf-noir theme at either end, with most of the dialogue backed only by neatly recorded sounds. This fits perfectly with the early-’60s aesthetic of 16mm black-and-white, with playful editing recalling the new-wave vibe of Eastern European cinema from that era.

The film is a fresh-out-of-the-gate triumph for young writer-director Juho Kuosmanen, starting with his casting of Jarkko Lahti, a blond bantam who, with his tousled hair and cocked smile, looks amazingly like the real Olli, a small-towner suddenly thrust into the Helsinki limelight in 1962, when he was chosen to defend Finland in the ring, on home turf. By this point, Mäki has won a number of European titles—all amateur—and he’s not that worried about hitting the bigs. That in itself is worrisome to Elis Ask (Eero Milonoff), a onetime boxing hotshot who has decided to groom the younger man in his image.

There’s something else Ask wishes Olli hadn’t told him; the latter has fallen in love with Raija (the winsome Oona Airola), a preschool teacher from back home. She accompanies him, rather chastely, to training sessions in the capital, and these also include being followed by a documentary film crew. She’s not that into boxing, or fame, for that matter, but Olli finds himself more interested in her than in losing the four or so pounds he needs to drop to qualify for the featherweight bout, to be held in the nation’s largest stadium.

As conflicts go, this is pretty mild, but the simple structure allows the filmmaker to tunnel back into the quietly hopeful side of that grey, postwar moment. And the sets and other period details add fascinating precision to this otherwise dreamlike fable of a small man’s reach for greatness. By the way, it doesn’t ruin the (historically ordained) ending to know that the real-life Olli and Raija play an elderly couple our screen duo encounters near a Helsinki harbour. “Do you think we’ll become like them?” the younger pair wonders about the other.