Jennifer Lopez has performed the first show of her Las Vegas residency.

a Rule made an appearance on stage twice, for 'I'm Real' and 'Ain't It Funny', while Jennifer was joined by Ne-Yo on 'Very Special'/'All I Have' - which saw the 'So Sick' hitmaker take on LL Cool J's parts - and the crowd was stunned when Pitbull emerged from under the stage for the final song of the evening, 'On the Floor'.

Among those in attendance for the show was Kelly Osbourne, who along with pal Rebel Wilson, couldn't contain her excitement.

Posting a selfie on Instagram from the audience, she wrote: "Two sexy bitches ready to watch @jlo! @rebelwilson and myself are pumped! #WaitingForTonight (sic)"

The two stars also shared pictures of themselves with singer Justin Bieber, who thought the 'All I Have' show was "incredible".

He tweeted: "Thank you @JLo for having me at opening night. Incredible show. Thanks and congrats."

'American Idol' host Ryan Seacrest was impressed by the show judge's hard work.

He posted: at "@JLo's vegas opening..hardest working women in show biz amazing! Congrats #jlovegas (sic)"

The first leg of the 'All I Have' show will run until February 9, and Jennifer will then return to Las Vegas on May 22 for performances until June 12.




Jennifer Lopez's 'All I Have' set list:

'If You Had My Love'

'Love Don't Cost a Thing'

'Got a Lot o' Livin' to Do'

'Get Right'

'I'm Real' (with Ja Rule)

'Feelin' So Good'

'Jenny From the Block'

'I'm Into You'

'Girls'

'Booty'

'Feel the Light'

'I Hope You Dance'

'Ain't It Funny' (with Ja Rule)

'Very Special'/'All I Have' (with Ne-Yo)

'Hold It Don't Drop It'

'Quimbara'

'Quien Sera'

'Let's Get Loud'

'Waiting for Tonight'

'Dance Again'

'On the Floor' (with Pitbull)