Tickets for Barbra Streisand's first UK gig in 13 years sold out in just 20 minutes, despite costing between £100 and £500.
Streisand says she had to overcome stage fright to tour
Within minutes of selling out the tickets were being resold at up to £3,550 a pair on auction websites.
A second date at the 02 arena - formerly the Millennium Dome - has now been added to her European tour.
Streisand's publicist said her concerts were on a par with those of Elvis Presley and Frank Sinatra.
Streisand, 65, said she had finally conquered the stage fright which had kept her from performing for 27 years when she toured the US last year.
"If I did not have stage fright I would have performed much more in my career," she added.
"I just never liked it. My heart pounds, I get palpitations - very, very uncomfortable and hard to sing. Fear takes over me. I do not even like to get up at a birthday party of my own and talk."