Karen Dunbar, Kings Theatre, Glasgow

"This is like being inside Elton John's heid," Karen Dunbar says as she staggers on stage in the guise of a sozzled, shoeless clubber and surveys the wedding-cake décor of the venerable Kings Theatre. And it seems fitting that Dunbar should sell out the historic home of variety and panto in the closing weekend of Glasgow's International Comedy Festival.

A hugely popular local comedian, Dunbar presents a variety show of sorts, with sketches and character-driven monologues. But it's all embellished with industrial-strength language and street insights reminiscent of Billy Connolly's epic observational arias - an inescapable comparison here.

And in the city of Connolly, where jagged garrulous humour is in the DNA, it is something of mystery that a fully fledged comedy festival took so long to emerge. They all scoffed when Tommy Shepherd, the dogged founder of Edinburgh's first permanent comedy club, The Stand, launched the event three years ago. But he's having the last laugh as Glasgow's third annual Comedy Festival - which has doubled in size and star wattage - closed so spectacularly. Edinburgh's overstuffed Fringe no longer has a monopoly.

In three weeks, Glasgow has seen a procession of comic royalty on re-energised form - everyone from Paul Merton to Harry Hill and Jimmy Carr has graced various stages. Yet Dunbar was the hottest ticket, one of few women to challenge the dominance of the testosterone rant, capitalising on her television success as the female face of BBC Scotland's cult smash Chewin' the Fat.

Her face is her fortune: a malleable, squelchy mouth (stretched to hilarious effect in her Julia Roberts impression) and wild popping eyes are the vital components of an array of characters. Her spin-off solo series, meanwhile, has been nominated for the Golden Rose of Montreaux awards.

On stage, she moves from straightforward stand-up into a flurry of changes, becoming a doddering yet sexually voracious pensioner with a wild past, a despairingly lonely shopkeeper, an uptight teacher and a sozzled party-girl trying to separate the remains of kebab from her mobile in her bag.

A sense of melancholy behind her various incarnations raises the material beyond cliché and lends them a desperately sad edge. But she has her clunky moments, especially a tendency to lace the show with cheesy songs in an over-familiar social-club singer routine. But her sheer chutzpah saves the day, along with bolts of a squirmingly recognisable reality drawn from her days as a karaoke compere.

By the frantic finale, she had slipped the (admittedly partisan) crowd into her battered handbag. Dunbar is tantalisingly close to breaking through to a much wider audience, and with more emphasis on her fragile yet outrageous characters, she just might follow a certain Mr Connolly on to the international stage.