"Headed to celebrate my friend's engagement," Handler captioned a clip on Instagram.
Paltrow wore a maroon dress with a one-shoulder, ruffled neckline. People reported the party was "very glamorous" but not "stuffy."
"Instead, lots of candles and fragrant flowers created a romantic atmosphere. It felt intimate and very special," a source said. "You could tell that all guests very much love the couple."
Paltrow posted a photo from her hotel room the day after the bash.
"The morning after #thenomadla," she captioned the picture.
The engagement party followed Paltrow's bachelorette getaway with Diaz, Stella McCartney and other pals in Mexico.
The actress, who was previously married to Chris Martin, got engaged to Falchuk in January after more than three years of dating.
"We feel incredibly lucky to have come together at this juncture in our lives when our collective successes and failures can serve as building blocks for a healthy and happy relationship," she said at the time.
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