The Caretaker (Old Vic)

What a performance rustles at the centre of this 1960 play by Harold Pinter. Rodent-faced and ratty haired, Timothy Spall plays a homeless man, Davies, who's taken in out of the perpetual rain by Daniel Mays' gentle Aston, and allowed to stay in his grotty, junk-filled attic. The flat's owned by his brother Mick – George MacKay, thin and sharp-edged as a flick knife – who plans to turn it into a penthouse. Davies sticks around like a bad smell; power struggles, naturally, ensue.

Directed by Matthew Warchus, this is an exceptionally funny rendition of Pinter's blackly comic play. Rather than fastidiously approach the placement of each line, each non-sequitur or each seemingly irrelevant babbling rant about going to Sidcup or the route of London buses, Warchus inflates the characters' idiomatic delivery. The result often results in proper out-loud guffawing.

Spall has blissful comic timing, turning those famous pauses into build-ups to punch-lines. Eyes as wild as his hair, he gives Davies a plethora of physical ticks and shuffling gestures, all wrapped in stained undergarments and a dishevelled suit: think Frank Gallagher of Shameless meets Bill Bailey in Black Books, with a side order of Godot's tramps. He's foul and grasping, yet also confused and pitiable; lines are gibbered and garbled, many muttered inward to himself or bursting with indignation. Such rhythms of the drunk, the damaged, may not be how you expect to hear Pinter delivered, but they're horribly recognisable: Davies is the kind of man we find ourselves walking a little faster past when he's incoherently shouting things on the street.

But not Aston. Aston takes him in, puts a (leaking) roof over his head. Mays' soft-centred, socially awkward performance is quiet and internal in contrast to Spall's gleeful grotesquery. Mays sits pigeon-toed, cradling a toaster he's perpetually trying to fix, or limps and stoops round the attic – fully realised in Rob Howell's design, from the disintegrating wallpaper to the teetering stacks of yellow newspapers to, yes, the rusty old kitchen sink.

Mays excels in a tender middle section, where we hear through a softly-delivered monologue how Aston was sent to a psychiatric hospital. "I got out of the place […] trouble was my thoughts had become very slow," he tells the uncomprehending Davies with real pathos.

The two brothers couldn't be more different: Mick brings the speed, and the menace, his triple-time monologues cut with an obscure threat. MacKay – previously directed by Warchus in his hit film Pride – has a deadpan delivery, mirthless expression and glitteringly hard-eyed stare at comic odds with his lithe physicality: he leaps like a cat onto the furniture, prowls around the room in his black leather jacket and Chelsea boots. MacKay rips through his speeches at applause-winning pace and a weirdly well-enunciated Cockney yowl, but although this finds the funnies, it loses some of the ominous weight of the words.

Still, I'd not really want anyone to slow down: the production already feels a bit water-logged at three hours, largely thanks to the decision to have two intervals which are neither needed nor justified here. But if the pace sags occasionally, when they're on fire, these three really crackle.

The Caretaker runs at the Old Vic unitl 14 May.