One hardly has to be the unlikely love-child of Sherlock Holmes and Miss Marple to deduce that something special was happening last night: touts buying not selling; a jam-packed, fervid Brixton Academy; a sense of occasion and, long after Kasabian had fled the stage following their solitary encore, the surreal experience of a crowd marching onto the streets of South London chanting the hook to the evening's farewell salute, L.S.F. (Lost Souls Forever).

Sometimes a band is so full of self-belief that - despite their limitations - their rise is unstoppable and, by some peculiar osmosis, that self-belief transfers to the mainstream.

Such a band is Kasabian, whose confidence never mutated into hubris and who succeeded via an appealing mix of force of will, songwriting craft and unadulterated charisma. Almost hypefree, the Leicester quintet have risen by stealth without the permission or support of the cognoscenti, but with the gradual acquisition of a fanatical audience which has grown by word of mouth, and all this before the release of their second album, Empire.

"People's band" is an overused phrase, but in Kasabian's case it rings true. Their music, a curious amalgamation of Oasis swagger, Stone Roses groove and Happy Mondays narcotic-swirl could hardly be more dated and less fashionable if they included a washboard player and covered James Blunt's finest.

Yet, they managed to sound fresh and not merely because of a laser-guided light show that helped transform a mere concert into a spectacle.

In Tom Meighan, they had a singer (imagine a likeable, more mobile, more interested Liam Gallagher) so watchable he could get away with a silly beard and so overwhelmed by the adoration flowing his way that he could say little more than "Thank you, Brixton" between songs.

The favourites from their 700,000-selling, self-titled first album rang loud and clear: Cutt Off, the peculiar saga of a drugs factory with a chorus catchy enough for Meat Loaf to devour; Club Foot which sparked delirium on the dance floor and Butcher's Blues, a more languid, sway-along affair.

If those songs had introduced Kasabian back in 2004, they have re-emerged reinvigorated and the Empire material was proof that they have already shed their first creative skin. Shoot The Runner was a Spirit In The Sky for the 21st Century, while Sun/Rise/Light/Flies displayed a new- found subtlety and The Doberman was a slower, more stately way forwards.

The crowd hollered themselves hoarse to the older material and lapped up the unknown newer fare.

When Empire arrives in a fortnight, Kasabian will be unstoppable: a few months ago, they were an outside bet. Right now, despite the best efforts of Razorlight and The Feeling, 2006 might just belong to them.