Reese Witherspoon had one of the best times of her life when she celebrated her upcoming 40th birthday with an advance party. The celebration was even attended by some of the biggest names in Hollywood.

The birthday girl’s party was held at the Warwick in Hollywood, California on Saturday. Witherspoon’s natal celebration was attended by family and friends, including the actress’ husband Jim Toth and her mother Betty. Some of the Hollywood A-listers, who partied with Witherspoon, included Jennifer Aniston and husband Justin Theroux, Robert Downey Jr. and wife Susan Downey, Courteney Cox, Nicole Kidman and husband Keith Urban, according to Entertainment Tonight.

Kate Hudson also joined the celebration, as well as Jason Bateman, Toby Maguire and wife Jennifer Meyer, Matthew McConaughey and wife Camila Alves, Taylor Swift, David Foster’s daughter Erin Foster and many more. However, the biggest surprise for the night was Swift’s performance of “Shake it Off.” Hudson even captured the moment in a Snapshot video that she captioned, “This beauty gave a little surprise for our bday girl.”

The “Bad Blood” crooner was not the only musician who took the stage during Witherspoon’s birthday party. Urban also gave a special performance that had the birthday celebrant joining him for an impromptu song number. Witherspoon sang Lynyrd Skynyrd's “Sweet Home Alabama” while Urban played the said tune on his guitar.

Hudson also shared some of the pictures and videos from the birthday event on social media, as stated in the same report. The celebrations continued well into the night. Hudson even uploaded a Snapshot post that showed the time as “2:07 am” and was captioned, "Reese got us out past our bed time."

Meanwhile, a source told Us Weekly magazine that both Hudson and Witherspoon had fun “tearing up the dance floor” during the party. The source also shared that the birthday girl left the party at around two in the morning. “She had the best time and didn’t want the night to end,” the source added.