Hot Vegas

Nick Jonas hosted a dance party complete with wild chicks, celeb cameos ... and a giant inflatable penis -- and even though it doesn't sound like it ... it was just another day at the office.

Nick was staying at the MGM Grand for the iHeart Radio Music Festival when he got the idea to surprise hotel guests with the elevator rager -- as a clever way to promote his song, "Levels."

We're told the MGM Grand gave Nick access to 2 lifts he rigged with hidden cameras so he could film the whole thing.

Labelmates Tove Lo, Pete Wentz, The Vamps and Shawn Mendes helped get the party started before the crew picked up a bachelorette party, and a Vegas tourist who had no problem taking off his shirt.

We gotta hand it to Nick, he's got a knack for hijacking things.

According to police docs, the stabbing went down at 7 AM on Labor Day ... which means it happened during the tail end of David Guetta's show. Skrillex and Diplo did not perform at XS until later that evening.

A violent fight was swept under the rug in Vegas over Labor Day, when 4 people were seriously stabbed night during a DJ's show at XS Nightclub.

Law enforcement tells TMZ, a huge fight involving around 20 people broke out in the middle of the show, leaving 4 with stab wounds. Our sources say it has all the markings of a gang fight.

We're told the injuries were serious including a punctured lung and spleen but everyone survived -- one victim admitted to gang ties and didn't want to go forward with any charges.

The world famous Penske Wynn Ferrari showroom at The Wynn in Las Vegas needs shelter, because they're getting evicted.

Our Wynn sources say the hotel mogul has been frustrated that he's not making the best use of the 10,000 square foot space inhabited by the high-end dealership. In other words, Wynn can make a killing renting to someone else.

So the dealership has till the end of the year to skedaddle.

The Wynn's Ferrari showroom was the only dealership in Nevada. Guests had to pay $10 to browse ... Ferrari owners oogled for free.

Justin Bieber had to square off with a ringside security guard just so he could get to his pal Floyd Mayweather Jr. to celebrate his victory.

The video is kinda bizarre ... since everyone knows Justin and Floyd are as tight as can be -- but one security guard apparently missed Bieber walking ... INTO THE RING with the champ.

Witnesses tell us Justin was actually in the ring until police politely asked him to step out during post-fight ceremonies. The video begins as Bieber tries to get back in, only to have the guard stand his ground and bark ..."You wanna be escorted out in handcuffs, young man?"

Britney Spears is now the reigning queen of Vegas, and she's already flexed her royal muscles in J Lo's face.

Britney just signed a 2-year extension on her Vegas residency at Planet Hollywood. J Lo will also be performing at the same venue beginning in January. Sources familiar with Britney's new deal tell us, the venue gave Britney first pick at concert dates and Lopez got to choose from what was left.

As for the new deal ... it's sweet. We're told Britney will make an additional $5 million for the extension. She is currently under a $30 million/2 year deal, but the new one will pay her $35 mil.

She'll also be doing fewer performances so she's making more per show.

Our sources says the new deal, with merchandising, could top Celine Dion.

Britney Spears and Sin City aren't breaking up just yet ... she's decided to extend her residency at The Axis in Planet Hollywood for another two years.

Brit made the announcement Wednesday night during her "Britney: Piece of Me" show.

As TMZ first reported, Brit's initial deal called for her to make $30 million over two years, but the show performed so well ... she quickly negotiated herself a pay bump.

The extension will give her 4 years on the Strip -- shy of Elvis Presley's 7-year run, but still impressive by today's standards.

Fun fact: Elvis got a staggering $500,000 just for his initial 4 weeks in Vegas ... in 1969!

Jesse Jane has a message for all the haters who still think she was drunk when she passed out in Vegas ... take a date rape drug and see what happens to you.

TMZ posted video of the porn star Tuesday in a stupor on the Vegas Strip.

Jesse is extremely upset by Internet users, whose comments include:

- "Tequila is no bueno, that's what u call white girl wasted."

- "It's hard to hold your liquor when you have no soul."

- "Just leave her on her back, that when she's most comfortable."

Jesse's now hurling back at all the trash talkers.

Porn star Jesse Jane says what looked like a case of her getting wasted Tuesday in Las Vegas was really the result of her getting roofied.

A rep for Jesse says she slammed 2 shots at a bar inside a Vegas hotel … problem is she got them from a stranger. Soon after, Jesse and her friends left the bar and she passed out cold on the Vegas Strip, which was when the video was shot.

Friends managed to get her back to her hotel room where she recovered. Jesse believes she was drugged because she woke up not remembering much, feeling weak and vomiting.

This is not the way you typically see porn legend Jesse Jane on her back -- she got so blasted in Las Vegas, she fell unconscious on a sidewalk in the middle of the day.

According to witnesses, 35-year-old Jesse was with a small group of friends on Tuesday when she went down across the street from Planet Hollywood Resort and Casino ... shortly after 1 PM.

You can tell from the video, Jesse is completely unresponsive. In other words ... her fun day in Vegas just took a turn for the worse. MUCH worse. We're told her friends eventually stopped trying to wake her up, and just carried her away.

AWESOME VIDEO ALERT ...

TMZ Sports is about to show you NFL legend -- and MMA fighter -- Herschel Walker dressed as Lady Gaga and dancing to "Luck Be A Lady Tonight" in front of a packed house in Las Vegas.

It happened Thursday night in Sin City when master ventriloquist Terry Fator called Herschel up on stage during his show at the Mirage ... and what came next was so epic, you just need to watch.

Celine Dion is back on the Strip -- after a year-long hiatus she returned to her Las Vegas residency at Caesars Palace.

The Colosseum was sold-out for CD's first show since last summer ... when she stepped aside to take care of her ailing husband, Rene Angelil, who's been recovering from cancer.

The 47-year-old still nailed the high notes while running through hits like "Because You Loved Me" and "My Heart Will Go On."

Celine's scheduled to do 40 shows between now and January ... for di world!

Kevin Federline has a devious plan to kick everyone's ass in his fantasy football league ... and it involves naked women and lots of vodka.

K-Fed typically hosts the fantasy football draft at his home, but this year he's decided to bring league members to Vegas. The draft will take place August 29 at the Crazy Horse III Gentleman's Club, where he's DJing.

Now here's the plan. Kevin doesn't drink anymore, but the other guys drink plenty and he's banking on them going into full intoxication mode, giving him a clear-minded advantage. He's also banking on the guys getting distracted by naked chicks, although Kev's not immune from that either.

Travis Scott beat on security guards at his concert to protect an extremely unruly fan, and it was all caught on video.

Scott was performing at the SLS in Vegas Tuesday night when a fan in the front row tried clawing his way on stage. Security stepped in, presumably to protect Travis. But the rapper turned on them.

The situation escalated as more guards got involved and Travis got more aggressive.

Richard Jefferson likely dropped some of his new Cleveland Cavaliers dough on a craps table in Las Vegas, where he was hanging with his ex-teammate Luke Walton -- and hauling in the chips.

Vegas sources tell TMZ Sports the former U of A Wildcats were doing some serious high rolling at Aria last weekend ... wagering anywhere between $600 and $1,000 on each roll. We're told Luke walked away with about $20k in winnings, and Richard did even better.

Talk about a great guys' weekend -- we got video of the duo boarding a Southwest flight for Vegas, and they told us the real reason for the trip ... their fantasy football draft.

Jefferson's got a good shot at his first NBA championship after signing with LeBron and the Cavs -- and, of course, Walton just won his 3rd title (as a Golden State asst. coach). But sounds like all the weekend smack talk was about their FF championship.

DeAndre Jordan was heckled on his way out of a Vegas pool party this weekend -- with people telling him he sucks and the Clippers suck as he left Wet Republic with Kevin Durant.

TMZ Sports spoke with Aloun Siharath -- a Vegas promoter who was walking with Jordan's entourage as they left the pool party at the MGM Grand ... who tells us Jordan and his pals were cool, calm and collected and never let the hecklers bother them.

In fact, in the video you can hear people yelling for security -- but we're told the situation didn't get to a point where anyone was arrested.

Jordan and Durant continued to party -- hitting up various nightclubs and parties ... and even hanging with former Clippers star Matt Barnes.

A massive fire erupted Saturday at The Cosmopolitan hotel on the Vegas Strip.

The entire pool area was consumed by flames sending guests scurrying for safety. At least one person has been reported injured.

Willie Nelson is scheduled to perform tomorrow night ... no word on whether the fire will have an impact on the show.