Bridesmaids (15)

Starring: Kristen Wiig, Maya Rudolph, Ellie Kemper, Rose Byrne

I'm still not sure how to say her name, but Kristen Wiig is on her way to being a huge star. For those of us who don't know Saturday Night Live and have glimpsed her only in minor-but-memorable comic fill-ins (Knocked Up, Adventureland) Wiig's writing and performing in Bridesmaids are nothing short of revelatory. She matches the delivery of a fine comedienne with the expressive charm of a serious actor, so that even when her character is immobilised with self-pity or clenched with envy she manages the remarkable trick of not getting on your nerves.

That character would be Annie, a pretty, single, thirtysomething who's just been asked by best friend Lillian (Maya Rudolph) to be her maid of honour. Of course Annie's delighted, though it also wakes her up to her own unsatisfactory status – single – and circumstances. Her Milwaukee cake shop went under in the recession, her car is a heap of junk, her flatmates are a pair of weird British siblings (Matt Lucas is one) and her mother is an affectionate but over-sharing oddball (the late Jill Clayburgh, in her last role). There's a handsome guy she has casual sex – sorry, "an adult sleepover" – with, but anyone can see he's a dickhead (played with worrying assurance by Jon Hamm). Still, now she can focus all her energies on helping Lillian with the wedding.

Then that gets sabotaged, too, once Lillian's new "best" friend Helen (Rose Byrne), a well-heeled, well-groomed beauty, usurps the role of chief wedding-planner. The signs aren't good from the off when, in a wonderful scene of oneupmanship, Helen gives such a fulsome toast at Lillian's engagement party that Annie is spurred into topping it. In front of the astonished guests they end up practically wrestling the microphone from one another before screeching out "That's What Friends Are For" in a sort of duet. Thus follows a wickedly unladylike comedy of competitive friendliness between flat-broke Annie and money-no-object Helen, with three other bridesmaids (Wendy McLendon-Covey, Melissa McCarthy, Ellie Kemper) holding on for dear life in their slipstream. Just how different it will be from your usual taffeta-and-hugs wedding comedy is evidenced when Lillian and her maids turn up at a posh bridal boutique for a fitting and realise that the lunch they've just eaten has given them food poisoning. How funny can the spectacle of fulminant diarrhoea on a shop floor be? Answer: really, excruciatingly funny.

If the scatological uncouthness evokes Judd Apatow's whiffy stable of male-anxiety comedies – The 40 Year Old Virgin, Knocked Up et al – that's hardly surprising, given Apatow is a producer here. Later, when the women are on a plane to Las Vegas for the hen night, you may be anticipating, as others already have, a chick-flick spin on The Hangover. True, there's the same concentrated sharpness in the writing, and an ensemble of comic faces refreshingly unknown to us, but the very fact that these are women behaving badly, in a much edgier group dynamic, ensures it's beholden to nothing.

And they never get to Vegas anyway, thanks to scenes on board the plane that twang another string on Wiig's bow: she can make drunkenness not only hilarious but believable.

She and her co-writer, Annie Mumolo, tend to write in long set-pieces, but that's no disadvantage when you've got genuine funny bones. They're funny about semen, and Air Marshals, and blowjobs, and being arrested, and even – in Annie's escalating row with a bolshy teenager – the C-word, which I didn't think was possible anymore.

Director Paul Feig, who has done a lot of TV comedy, doesn't overstretch the material, and he's extremely good with actors. With her beanpole body and mobile features, Wiig is evidently the star, but her script has given generous room to others, notably Melissa McCarthy as a butch, plain-speaking hoyden with the build of a prop forward. Maya Rudolph as the bride-to-be is also terrific, first in the one-to-ones with Wiig that establish the film's tender heart, and later in her reaction to Annie's explosive public meltdown: "Why can't you be happy for me, then go home and talk about me behind my back like a normal person?" There's even a decent role for a man, the Irish actor Chris O'Dowd playing a sweet-natured traffic cop who falls for Annie and looks so crestfallen when his good intentions go awry.

Men, however, are on the margins here, which is as it should be. Bridesmaids is at one level a riposte to the idea (as argued by Christopher Hitchens) that women aren't or else can't be funny. Wiig has kicked that one right into touch. Yet the film is also a corrective to their own sex as portrayed by Hollywood in those atrocious touchy-feely sisterhood flicks about the Divine Ya-Yas and the Travelling Pants, and what shows up the shopping and clucking of Sex and The City 2 as the terminal disgrace that it is.

This film understands the importance and durability of female friendship, while declining to sugar-coat the less palatable elements beneath the surface, such as the way women subtly undermine and compete with one another, prey on each other's weaknesses, or use their own neuroses as a stick to beat others. Yet it's also non-judgmental, portraying meanness and malice without partaking of it; even Rose Byrne's Helen, the least likeable of all the women, is shown to be weak rather than wicked. Through a combination of smart performances and scurrilous gags Bridesmaids yanks the buddy comedy from the hands of its traditional owners.