David Becker/Getty ImagesWhen it comes to striking a fierce pose, Jennifer Lopez knows how to nail it.
The 43-year-old Parker star looked stunning at the opening of Hakkasan nightclub at the MGM Grand Hotel & Casino in Las Vegas Saturday night, rocking a black halter dress with her hair pulled up in a high ponytail.
Lopez's 26-year-old boyfriend, Casper Smart, joined her for the night out on the town, sporting a red blazer for the event.
The couple kicked off their evening before partying the night away by dining in a private area near Pharrell Williams, who was celebrating his 40th birthday at the club.
After dinner, J.Lo and her beau held hands as they walked to the blue carpet, and then headed inside, grabbing a seat near Vanessa Hudgens and her boyfriend Austin Butler's booth.
Williams was later surprised at about 1 a.m. with a three-tiered ombre blue and gold birthday cake, complete with a champagne toast to ring in his big 4-0.
Hakkasan Las Vegas and GQ Magazine hosted the private VIP event, in which celebs like Mark Salling, Smallville's Tom Welling, Dancing With the Stars' Cheryl Burke and Calvin Harris were also in attendance, enjoying champagne, cocktails and hors d'oeuvres throughout the evening.
The affair was also a celebration for Grammy-winning "We Found Love" producer and DJ Harris, who launched his exclusive residency at the event and spun hits for partygoers as well.