Surprise performance: Ahead of her scheduled conert at the MGM Grand, she put on a surprise show at Vegas club Krave at Planet Hollywood

Risqué ensemble: Lady Gaga wore a very revealing outfit of sheer mesh that clearly showed her G-string and lack of bra

Gaga is renowned for her surprise shows and her latest took place at Krave nightclub at Planet Hollywood, where she popped in to sing Born This Way to club goers.

The following night she headed to the famed MGM Grand Hotel and Casino as part of her Monster Ball Tour.

Despite starting her show almost an hour late, the Bad Romance singer still received cheers and whistles as she took to the stage in Sin City.

Blondie: Gaga threw around her long blonde hair extensions on stage as she sang her hit Born This Way

Monster Ball Tour: Gaga performed her scheduled concert the following night at the MGM Grand in Las Vegas

During her set she changed into a red priest-inspired robe, which she accompanied with black knee-high boots and fishnet tights.

And the star, real name Stefani Germanotta, wasn’t the only person singing during the concert, as he fans paid tribute to her by singing happy birthday to Gaga.

Quick change: During her set she changed into a red priest-inspired robe, which she accompanied with black knee-high boots and fishnet tights

Supporting act: Scissor Sisters Ana Matronic and Jake Shears opened Lady Gaga’s concert for her in Las Vegas

To die for: Lady Gaga tweeted this bizarre picture of her meeting with rock legend Alice Cooper after a concert in Phoenix, Arizona

The New York-born performer turns 25 on Monday and her fans made sure to show their love for her with the tribute.

After the Scissor Sisters opened for her show, Gaga performed a mixture of hits, including Born This Way, which has been at No.1 on the Billboard charts for six weeks.

Meanwhile, on the same night that Gaga was putting on her show at the MGM Grand, The Black Eyed Peas singer Fergie was celebrating her 36th birthday at the Bellagio Resort and Casino in Vegas too.

And Britney Spears was also following the Las Vegas trend by performing at the Rain at the Palms on the same night.

It was Britney’s first live performance since the end of her The Circus Starring Britney Spears tour in November 2009.

She sung a selection of songs from her upcoming new album Femme Fatale in a skin-tight leather bodysuit.

Despite it being Lady Gaga’s birthday on Monday, she’ll still be working on the special day, with her next concert being at the Staples Center in Los Angeles.