When she got into it she was really good

Mark Collins

Earlier her director husband, Guy Ritchie, entered the theatre by the stage door and left half-an-hour later with son Rocco, about an hour before the performance started.

Many of those who saw the production thought the singer improved as she grew more confident in the second half.

Victoria Bateman, 32, said: "I thought she was a lot better than expected, she was excellent."

Malva Green, 41, said: "She was nervous to start with but got a lot better."

Mark Collins, 28, said he did not think Madonna put in the show's best performance, but added: "When she got into it she was really good."

Success

Madonna stars in the play, penned by Australian David Williamson, as an art dealer who tries to manipulate her friends when a Jackson Pollock painting goes on the market.

The press has only been allowed a sneak glimpse so far

The play has already been a massive success in Australia, breaking box office records in Sydney.

The cast of seven are directed by Laurence Boswell, whose recent credits include A Day In The Life Of Joe Egg and Popcorn, by Ben Elton.

Preparations for the play were hit early on when matinee performances were dropped because of Madonna's recording commitments.

The singer's West End stage debut was also delayed by technical problems.

Hollywood rivals

The show officially opens on 23 May for a 10-week run.

Madonna has also appeared on stage with then husband Sean Penn in the 1986 off-Broadway play Goose and Tomtom.

The singer has also appeared in various films. Before finding fame, she wrote her own part in a filmed stage play called In Artificial Light in 1980.

After good reviews for her role in the film Desperately Seeking Susan in 1985, Madonna fared less well with 1986's Shanghai Surprise and Who's That Girl a year later.

Gwyneth Paltrow is also treading the West End boards

A more recent musical performance as Eva Peron in Evita earned her better reviews, but her role in The Next Best Thing received a mixed reception.

Madonna will next be seen in her husband Guy Ritchie's new movie Swept Away.

She is also reportedly making a cameo appearance in the new James Bond movie, for which she sings the theme tune.

Madonna will be competing for audience members with her good actress friend Gwyneth Paltrow.

Hollywood star Paltrow is starring in her West End debut Proof at the Donmar Warehouse.

Madonna and Paltrow are just the latest US celebrities to tread the boards in the West End, including Kevin Spacey and Nicole Kidman.

Also currently performing in the capital are Matt Damon, Casey Affleck and Summer Phoenix, who are all appearing in the play This Is Our Youth.