THEATRE / Chimps Hampstead Theatre, London

Who would have guessed that art works would provide the climax for not one but two of this year's dramas? However, just as Yasmina Reza's smash-hit Art is less a comedy about modern art than a dark dissection of male values, Simon Block's tightly constructed Chimps appears to be a very funny play about pressure-selling but turns out to be a tart addition to the fashionable subject of men behaving badly.

Mark (Darren Tighe) is less a case of being downright bad than fatally feckless. He and his pregnant girlfriend, Stevie (Ashley Jensen), met at art college. She now works as a graphic designer, but he has quit a dead-end job to pursue his dream of becoming an illustrator, leaving her to shoulder the mortgage. The plastic covers are still on the sofa in the front room of Bruce Macadie's neat, atmospheric set, but while Mark and Stevie's new life in a barely affordable North London home looks safe, cracks are beginning to appear. Or so salesmen Lawrence and Gabriel would have them believe. Taking advantage of Mark's easygoing nature, the men inveigle their way into the house and a light situation comedy turns into a situation nightmare with the announcement that the back wall is about to fall down.

Like David Mamet's Glengarry Glen Ross, to which this is something of a suburban cousin, Block's thoroughly enjoyable play is obsessed with the deal and the jargon-filled language that clinches it. "We're not wideboys. Our firm is famously narrow," claim the savvy, sinister salesmen who have their own ABC: Always Be Closing. Experts in "the science of stress", they are actually masters of manipulation, massaging Mark's weakness and playing horrifying (yet hilarious) power games, aiming for the magic moment when the hapless couple sign up for 25 years' worth of Excote, a silicon- based water-repellent. Cunningly, instead of merely following the crime, Block allows us in on the set-up, thus revealing unexpected layers. The excellent Nicholas Woodeson gives a fine Bob Hoskins-style performance as Lawrence, a drowning, middle-aged man struggling to hold on to a job and his self-esteem, while Fraser James's silver-tongued meekness is peeled back to reveal a controlling will of iron.

Mark's vulnerability and Stevie's frank disbelief prove fertile ground for the men's gripping "divide and rule" game and Block's stranglehold grows ever tighter as the play progresses. "There's no such thing as the perfect couple," Gabriel teaches. "Feel for the cracks and apply pressure." Block's dialogue can't quite sustain his occasional philosophical digs and the unlikely premise induces scepticism, but his observation and the strung-out tension as Mark and Stevie struggle to sort out their differences in the jaws of the brilliantly sprung trap is thrillingly unbearable.

The expertly timed laughs in Gemma Bodinetz's marvellously played production guarantee a good time, let alone Ashley Jensen's steadfast, heartfelt depiction of a woman struggling to face the truth of her relationship. A hit? A dead cert. It's as safe as houses.

To 16 Aug. Booking: 0171-722 9301

David Benedict