A SEMI-naked Lady Gaga crashed an Islington gig on Wednesday night and gave an impromptu performance in her bra.

The pop superstar surprised gig-goers at the O2 Academy 2 Islington when she joined New York band Semi Precious Weapons onstage for two songs.

The chart-topper put in an energetic turn in front of an adoring crowd at the 250-capacity venue, in the N1 Centre, in Parkfield Street, Islington, singing and at one point thrashing at the drum kit.

She then jumped into the audience and attempted to crowd surf before quickly being pulled out by security.

Semi Precious Weapons have supported Lady Gaga over the past year and opened for her at the O2 Arena, in Greenwich, last night (Thursday December 17) as part of her Monster Ball world tour.