JLS, Hammersmith Apollo, London

Oh, how the girls screamed. They screamed and cried then screamed some more. For 90 minutes the most ear-piercing sound imaginable did not cease. The reason? JLS, boyband du jour, are in town.

In the final of the 2008 edition of The X Factor, Aston, Oritsé, JB and Marvin looked on as Alexandra Burke was crowned as the winner. Tonight, JLS are on top of the world. Since the talent show the boys have signed to Epic records, after a certain Mr Cowell passed on them, and have seen their eponymous debut album outsell Burke's Overcome by around two to one. They have had two No 1 singles and a No 1 album; they have received two MOBO awards; and they have collected three Brit nominations, including Best British Group. Burke is not doing too badly herself, but it is pretty clear who the real winners are.

The boys arrive on stage looking like Action Men. Or R'n'B Kens, if you will. They all sport sunglasses, leather and denim, accessorised with ripped muscles. Gone are the adolescent, matching coloured hoodies in which they paraded on The X-Factor – they have the urban pop star look nailed.

The best thing about the boys (apart from Marvin's arms) is their choreography. Their moves are slick, effortless and modern and they move about the stage with attitude. Aston is the stand-out performer and crowd favourite, arriving on stage for a Michael Jackson medley by doing a back flip from an upper level, before nonchalantly dusting off his shoulder and going straight into song.

But they're not all about the dancing. During the ballad section, the boys showcase the vocal ability which got them noticed in the first place. Songs like "Only Making Love" and "If I Ever" prove they can really sing.

Sure, there are some stomach-turningly cheesy moments, such as when a backdrop video projects close-ups of the boys' naked torsos, with the lyrics of "Kickstart" tattooed upon them. When the band do their signature move, of lifting their tops slowly to reveal their six packs (or in some cases, eight packs), it feels a little like a tacky hen night. But it's just saucy fun and it works. JLS have a sense of humour and the audience goes wild for it.

The guys also succeed in the rather arduous task of making every single girl in the room feel special. They point to specific girls and smile, kiss audience members' hands, wave at the hysterical crowd. Heck, I felt special by the time I left. Having been an anonymous face in a sea of thousands, that was no small feat.

The night is not without it problems, however. While the singles "Beat Again" and "Everybody in Love" are strong hits, there are more than a few lacklustre numbers complete with lazy titles: "Crazy For You", "Close To You", "Keep You". You get the idea. Many of their album tracks are forgettable fare and it takes some well chosen covers, like Rihanna's "Umbrella", to save the night. JLS's lyrics do not stray too far from talk of "pretty faces" and "beautiful girls", and the songs are peppered with plenty of "baby", but I'm pretty sure no-one was there for insightful poetic musings. It is a formula that works and JLS have seamlessly filled a need for a young, street boyband.

One thing is for sure – the boys have outgrown even such a sizeable venue as the Hammersmith Apollo. There is already talk of an arena tour, which really will be a show to see. And to invest in earplugs for.