Athol Fugard’s 1982 apartheid-era drama “Master Harold...and the Boys,” no doubt the finest play written by the 84-year-old South African writer-director, proves to be both timeless and timely in the Signature Theatre Company’s excellent new Off-Broadway revival, which Fugard himself has directed.

Intimate and tightly constructed, sharply political and emotionally bruising, autobiographical yet universal, despairing but with a glimmer of hope, the drama uses the fragile relationship between a white schoolboy and his family’s longtime black servants to tackle the tense cultural climate of South Africa circa 1950.

It opens on a rainy afternoon in an empty tea shop, where Sam (Leon Addison Brown) and Willie (Sahr Ngaujah) alternate cleaning up with joking around and practicing their ballroom-dancing abilities. They are soon interrupted by the arrival of Hally (Noah Robbins), the teenage son of the shop’s owner.

Their playful mood is shattered when Hally learns that his physically incapacitated, frequently inebriated father is coming home from the hospital. Hally reacts to the news by lashing out at Sam and Willie and adopting the racist attitude practiced by his father, leading to several dramatic gestures and a heartfelt, pained speech from Sam, who has served as a surrogate father to Hally.

Following an election season where personal frustrations inspired disturbing manifestations of racial and ethnic prejudice, the play is quite pertinent today. But even if that were not the case, it would still pack a strong punch simply because it is a masterful and accessible piece of writing.

Robbins brings a restless quality to Hally that makes his sudden transition into spiteful behavior all the more believable. By comparison, Brown presents Sam as sunny and genuinely loving, which makes his reaction to Hally especially heartbreaking.