Happy birthday, Sofia Richie!

The model turned 21 on Saturday and celebrated with her boyfriend of two years Scott Disick, plus Kylie Jenner, and mutual friends Anastasia "Stassie" Karanikolaou, Yris PalmerVictoria Villarroel and Amber Asaly in Las Vegas.

Sofia kicked off the festivities early at home in Los Angeles, where Scott surprised her with an Aston Martin! Do you like luxury...

The group then jetted off to Sin City, where they spent the afternoon at Encore Beach Club at Wynn Las Vegas. They enjoyed dinner Cipriani Las Vegas in Wynn Plaza and had a birthday toast with Perrier-Jouët Champagne. Venue performers cheered on Sofia, who wore a red studded bikini and white sheer mini skirt, with a name banner and other signs reading "21."

They then headed to the resort's XS Nightclub, where The Chainsmokers performed. Wearing a pink Swarovski-covered long sleeve Yousef Al-Jasmi jumpsuit, Sofia entered the venue together with Scott. She was greeted by resident performers holding another "Sofia" banner, plus drummers, a confetti parade with a multi-tier birthday cake. The couple danced and were in great spirits. The Chainsmokers' Drew Taggart later had Sofia join him on stage and had the crowd sing her "Happy Birthday." She and her girlfriends were spotted dancing and jumping around onstage, and they also did shots. Scott did not drink throughout the night, a source told E! News.

Wearing a pink latex dress, Kylie arrived later and joined the ladies. At one point, she lifted up Sofia and twirled her around in celebration.

"Kylie was in a great mood, smiling the whole night, while making sure Sofia was having the best time, dancing with her and twirling Sofia around their private VIP area," the source told E! News. "Kylie stayed about 30 minutes before departing early, ahead of the rest of the group."

"Later in the night, Vinny Guadagnino from Jersey Shore showed up and joined in on the celebrations," the source continued. "At one point, Sofia and Vinny faced off in heated dance-off against one another in the DJ booth as The Chainsmokers performed."

Sofia and her group headed back to their private jet around 4 a.m. for the 45-minute journey back to L.A., as seen on Sofia's Instagram Story.

See photos from Sofia Richie's birthday celebration in Vegas:

Sofia Richie, 21st, Birthday, Las Vegas, Scott Disick

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, 21st, Birthday, Las Vegas, Scott Disick

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, 21st, Birthday, Las Vegas, Kylie Jenner

Instagram / Kylie Jenner

Sofia Richie, 21st, Birthday, Las Vegas, Kylie Jenner

Instagram / Kylie Jenner

Sofia Richie, 21st, Birthday, Las Vegas, Chainsmokers

Instagram / Victoria Villarroel

Sofia Richie, 21st, Birthday, Las Vegas

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, 21st, Birthday, Las Vegas, Vinny Guadagnino

Instagram / Vinny Guadagnino

Sofia Richie, 21st, Birthday, Las Vegas

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, 21st, Birthday, Las Vegas

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, 21st, Birthday, Las Vegas

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, 21st, Birthday, Las Vegas

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, 21st, Birthday, Las Vegas

Denise Truscello / Getty Images for Wynn Nightlife

Sofia Richie, Victoria Villarroel, Amber Asaly, 21st birthday

Denise Truscello/Getty Images for Wynn Nightlife

Sofia Richie, Scott Disick, 21st birthday

Denise Truscello/Getty Images for Wynn Nightlife

Sofia Richie, 21st Birthday, Instagram

Instagram

Sofia Richie, 21st, Birthday, Las Vegas

Instagram / Sofia Richie

Sofia Richie, 21st Birthday, Instagram

Instagram

Sofia Richie, 21st Birthday, Instagram

Instagram

Sofia Richie, 21st Birthday, Instagram

Instagram

Sofia Richie, 21st Birthday, Instagram

Instagram

Sofia Richie, 21st Birthday, Instagram

Instagram

Sofia Richie, 21st Birthday, Instagram

Instagram

Sofia Richie, 21st, Birthday, Gifts, Instagram

Instagram / Sofia Richie

Sofia Richie, 21st, Birthday, Gifts, Instagram

Instagram / Sofia Richie

Sofia Richie, 21st, Birthday, Gifts, Instagram

Instagram / Sofia Richie

Last year, Scott took Sofia on a trip to Punta Mita, Mexico for her 20th birthday.

Watch Keeping Up With the Kardashians when it returns for season 17 on September 8 at 9/8c only on E!

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