VIDEO: GREASE Stars Olivia Newton-John & Didi Conn Reunite in Vegas

It was a GREASE reunion for Olivia Newton-John and Didi Conn in Las Vegas on Saturday night, January 3rd. The actresses, who portrayed Rydell High besties Sandy and Frenchy in the classic 1978 film, came together on stage at the Flamingo Hotel Casino during Newton-John's show.

Wearing black and pink jackets in tribute to their high school greaser girl days as members of the Pink Ladies, the duo sang "Summer Nights" from the film's best-selling soundtrack. Below, check out images from the nostolgic reunion!

Olivia Newton-John: Summer Nights show at The Flamingo Hotel features an eight-piece band and includes numerous Grease throwbacks, including "Hopelessly Devoted to You" and "You're The One That I Want," as well as Newton-John's single "Physical."

GREASE, the 1971 musical by Jim Jacobs and Warren Casey, is set in 1959 at fictional Rydell High School and follows ten working-class teenagers as they navigate the complexities of peer pressure, politics, personal core values, and love.

At the time that it closed on Broadway in 1980, Grease's 3,388-performance run was the longest yet in Broadway history, although it was surpassed by A Chorus Line a few years later. It went on to become a West End hit, a hugely successful film, starring John Travolta, Olivia Newton-John, Stockard Channing, and Jeff Conaway, two popular Broadway revivals in 1994 and 2007, and a staple of regional theatre, summer stock, and community theatre.