Lady Gaga's 30th birthday party was the place to be Saturday night.
The pop star celebrated at the No Name club in Hollywood with fiancé and Chicago Fire actor Taylor Kinney, 34, as well as a slew of celebrity friends. Gaga, who turns 30 on Monday, wore a glittering gold boat neck Saint Laurent fall 2016 Ready-to-Wear mini dress with puffed up short sleeves and thick black belt, paired with black strappy platform peep-toe pumps and a sparkling Lorraine Schwartz choker. Kinney wore a black suit jacket, shirt and jeans.
In addition, Gaga performed at the party, which many guests said was the best part of the night.
"She sounded amazing," a source told E! News exclusively.
Swift, who wore a loose-fitting black, shimmering jumpsuit, gave Gaga a huge hug and danced with her and Hudson. She was also seen talking to del Rey and Williams.
"Everyone sang 'Happy Birthday' to Gaga and it was a perfect night," the source added.
Teigen, who wore a black outfit as well, is weeks away from giving birth to her and Legend's first child. She had a lot of energy at the party and she and her hubby shared many kisses, the source told E! News.
Teigen and Legend celebrated their upcoming arrival at their second baby shower, along with pals such as the Kardashians, in Los Angeles earlier that day.
The party continued until the early hours of the morning. Hudson, who wore a plunging, half-sheer black dress, left around 4 a.m. alone, another source told E! News exclusively.
She and Jonas, who sported a black tux, arrived at the party separately, the source added. The two had sparked romance rumors last September and have been spotted out together in recent months but have never confirmed a relationship.
Jonas arrived with Swift and Lorde in Swift's car and they all left together around 1 a.m, another source told E! News. The three had hung out at The Nice Guy restaurant the night before.