First Night: Don Juan in Soho, Donmar Warehouse, London

Seduced by Marber's 21st-century aristocrat

There's a moment in the first act of Don Juan in Soho when Stan, DJ's faithful sidekick, turns to the audience and begs: "Please don't be charmed, he's not a loveable rogue." His pleas are in vain.

Almost from the moment Rhys Ifans strides lankily on to the stage, the image of the modern-day Lothario with skinny trews and a Stringfellow blond bouffant of hair, we are seduced.

This is the legend of Don Juan according to Patrick Marber who has taken Molière's 1665 comedy and let his modern-day aristocratic wastrel loose among the fleshpots of London's Soho.

Since its first appearance in the 17th century there have been some 1,700 retellings of the tale of the amoral libertine who gets his comeuppance at the hands of a stone statue. Marber, our Molière and chronicler of vice, from gambling (Dealer's Choice) to infidelity (Closer) and showbiz emptiness (Howard Katz) would seem to be the perfect man to provide a Noughties version.

Don Juan in Soho is less dark than Marber's previous works, a louche, drug-and-libido-fuelled romp and a love letter to the seamier side of life in London . As expected, the writing is taut and sharp and Michael Grandage's production is slick with a variously-lit back curtain providing quick location changes and a frantic soundtrack conjuring up the nocturnal city.

We are introduced to DJ - "he's in the penthouse, banging a Croatian supermodel" - by Stan, whose main role is "keeper of the Blackberry" on which DJ stores a record of his 5,000 conquests. When the "Kofi Annan of copulation" emerges, he shrugs off the end of his marriage to Elvira, a pious aid worker, as mere "collateral damage". But this heartlessness is, of course, his undoing. Marber preserves the vengeful statue of the original - a hilariously shonky Charles II who drives DJ to his death in a West End rickshaw bedecked with fairy lights - but it is Elvira's brothers who wreak the final, fatal revenge.

Ifans is a tour de force as the eponymous hero - the comic lovechild of Rik Mayall and Peter Cook (whom he played in Not Only But Always). Chin dusted in cocaine, enrobed in a silk dressing gown he throws himself into his debauchery with zeal, pausing for breath only when his ageing father arrives (a nice doddery turn by David Ryall). He is supported by a zesty cast who never let the energy levels drop, although Laura Pyper's Elvira (admittedly a difficult character to warm to) is a little hysterical.

Marber doesn't overcome all the problems of transposing a 17th-century comic satire to the modern day. He has preserved some of its tropes - the comic asides, the stock characters - but this results in some worryingly unreconstructed attitudes to class and race. DJ is thankfully a more complex figure - amoral, but with a streak of integrity as he rails against hypocrisy, lily-livered liberalism and celebrity culture. When he is dispatched by Elvira's clan, rather than perhaps dying alone in his idea of hell ("where there are no lights, no people"), the ending falls a little flat.

Don Juan in Soho is not flawless, but with Marber's razor-sharp wit and Ifans' whirlwind performance there is surely no better adult (in both senses of the word) Christmas show on the circuit.