Penelope Cruz Got Julia Roberts to Sing 'I Say a Little Prayer' and It's the Best Instagram Video Ever

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Julia Roberts
relived a classic scene from her beloved rom-com My Best Friend's Wedding last week, with a little help form Penelope Cruz.

At Lancome's Stars & Wonders gala in Monaco, California, on Wednesday, one of the bands that played the event covered the classic Dionne Warwick tune "I Say a Little Prayer," and Cruz captured the moment on Instagram.

WATCH: Julia Roberts 'Can't Wait' For Daughter Hazel to See 'My Best Friend's Wedding': 'That'll Be Sweet'

Walking around the gala, Cruz lead a lip sync singalong that included a couple of big name stars and culminated with a beaming Roberts joining in on the fun.

WATCH: Dermot Mulroney Gushes Over Julia Roberts at Guys' Choice Awards: 'I'd Walk a Mile on Broken Glass For Her'

The iconic song played a big role in My Best Friend's Wedding, in a scene where Rupert Everett's character convinces everyone in a restaurant -- including Roberts, Cameron Diaz and Dermot Mulroney -- to sing the song along with him.

At the gala, Cruz also posed alongside Roberts and fellow Oscar winner Kate Winslet for a cute photo on the red carpet.

WATCH: Julia Roberts Says She Refused to 'Shimmy Down a Well in a Micro Mini' for 'Erin Brockovich'

This has been a big week for the Pretty Woman star. Recently, she was named People's World's Most Beautiful Woman for a record fifth time -- and the first time in 26 years. Check out the video below to hear more.