Jamie Lloyd's pitch-perfect production of The Caretaker serves renewed notice that Harold Pinter has written nothing sadder, more bleakly humorous or likely to survive as a classic of post-war British theatre.

It is the finest version of the play I have seen. Lloyd captures as rarely before the Beckettian, long-distance loneliness, mental disturbance and alienation of its three characters.

Aston and Mick, two youngish brothers, and Davies, the homeless tramp, are caught in a power battle that centres upon a filthy room full of junk. Staged in depression's twilight, Soutra Gilmour's wonderful set teems with mounds of discarded, dilapidated bric-a-brac.

All three men cling to the illusion that their dreams of security lie just around the corner or at least within grasp. If only Mick could transform the room into a penthouse apartment, if only Aston built his shed in the garden and Davies collected his mysterious papers from unreachable Sidcup all might be well.

The action of The Caretaker deals less with the confounding of these vain hopes than upon the comic process by which the wheedling grumbler of a tramp attempts to play one brother against the other in a bid to secure himself a billet.

First teased by Nigel Harman's superlative, sadistically playful Mick, then tormented, the vagrant is finally expelled from the room, all hope gone.

David Bradley's definitive Davies is an involuntary traveller with at least two unfixed identities, whose papers, memories and possessions have variously been left mouldering in Sidcup, Luton, Shoreditch and Acton.

He offers the key to the production's triumph. From Donald Pleasance to Michael Gambon, Davies has been played as a figure possessed by menacing guile and aggression.

Bradley's revelatory performance emphasises, without sentimentality, the desperation and pathos rather than power of this nasty old man, a would-be go-getter who reeks of dirt, racism and ingratitude.

A long-haired, tottering fugitive from the cold, eyes all questing blankness, Bradley's tramp has the winded air of a destitute no-hoper, used to clutching at straws in the wind, who snarls in his bad dreams.

Con O'Neill's high-voiced, suited Aston, beautifully captures the bemused detachment of a man numbed by electric shock treatment.

Nigel Harman's indelible Mick, who saves his brother from the tramp's treachery, casts a sinister glow upon these dark intrigues. Spell-binding.

• Closes 14 April. Information: 020 7328