\"Half a century young!\" a defiant lead singer John Lydon shouted to thousands of fans at a packed Brixton Academy in south London.

Sporting his trademark spiky orange hair, the performer best known as Johnny Rotten wasted no time poking fun at the British establishment.

He wore a pheasant shooting outfit, which caused him several wardrobe malfunctions when his trousers kept slipping down, and the patriotic war-time song \"There\'ll Always Be An England\" blasted over the speakers before the set began.

The four punk pioneers opened with Pretty Vacant, and raced through most of their best known numbers in a gig that lasted just over an hour. Predictably it was God Save The Queen and Anarchy In The UK that raised the roof.

The capacity crowd united Pistols contemporaries, most of them male and balding, with younger listeners keen to find out what all the fuss was about.

\"Anyone under 40 in the crowd?\" Lydon joked.

When the Pistols burst on to the music scene in the late 1970s they caused a sensation, and their album Never Mind the Bollocks ... Here\'s the Sex Pistols, released 30 years ago, is considered one of the most influential in rock\'n\'roll history.

READING LYRICS?

Lydon, 51, appeared to be referring to a crib sheet during the songs after he forgot some lyrics during a smaller warm-up concert last month in Los Angeles.

He was performing alongside guitarist Steve Jones, 52, bass player Glen Matlock and drummer Paul Cook, both 51.

A handful of fans wondered if another comeback tour was really the stuff of genuine rock rebels.

\"May be I was a bit surprised they\'d done this,\" said Steve, a 46-year-old Londoner. \"A one-off concert, may be, but a load of them seems a bit of a sellout.\"

But generally the boisterous crowd did not care on a night of nostalgia and non-stop noise during which Lydon engaged them with his trademark expletive-ridden banter.

The band plays four more concerts in Brixton followed by shows in Manchester and Glasgow.

The Sex Pistols formed in 1975, united by limited musical ability and a vague belief that they had an alternative to the pompous music of the day.

Matlock, a key songwriter, was ousted in early 1977. He was replaced by Sid Vicious, who could not play bass at all but is considered the band\'s best-known member.

Never Mind the Bollocks topped the charts in 1977 but Lydon quit the following January during a disastrous American tour. Vicious died of a drug overdose in 1979.

The band first reunited in 1996 for their Filthy Lucre Tour and then again in 2002 and 2003. The Sex Pistols were inducted into the Rock and Roll Hall of Fame last year but refused to show up, sending a rude, handwritten note instead.