Jeffrey Mayer/WireImage
March 21, 2016

Hollywood's A-list was out in full force to celebrate Reese Witherspoon's 40th birthday over the weekend. Even her mom, Betty, flew in for the occasion—and to "get crazy on the dance floor":

Crazy on the dance floor? 🎉🎉🎉 #BirthdayWeekend #MomsInTown 🎂🍧

A video posted by Reese Witherspoon (@reesewitherspoon) on

In a night that included plenty of celebrity cameos and performances (including a surprise set from Taylor Swift!) it was the birthday girl herself who ruled the stage. At one point The Sweet Home Alabama star and proud southern belle joined Keith Urban for a special performance of Lynyrd Skynyrd's classic "Sweet Home Alabama." And Vanity Fair writer Derek Blasberg caught the amazing moment on video. Watch it here:

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"You can take the girl out the South, but you can't take Sweet Home Alabama out the girl! HAPPY BIRTHDAY @reesewitherspoon (cc @keithurban)," he wrote in the post.

Author Cheryl Strayed (who penned Wild) was also in attendance, and stopped for a fangirl moment with Swift and actress Laura Dern:

Um.. @taylorswift @lauradern #happybirthdayreese

A photo posted by Cheryl Strayed (@cherylstrayed) on

"Um.. @taylorswift @lauradern #happybirthdayreese" she captioned the snap.

Witherspoon's actual birthday is Tuesday, March 22.