The actress, who plays Haley Dunphy in the hit comedy, looked gorgeous in her midnight blue dress as she walked the red carpet in Los Angeles on Monday night (5 August).
Sarah was clearly impressed by what she saw on screen as she tweeted afterwards: "Just left the #LoveLace premiere and I have to say that it is the best film I've seen all year! Thanks for inviting me @WeinsteinFilms!"
Lovelace is a biographical film about porn star Linda Lovelace, who is played on screen by Amanda Seyfried.
Meanwhile, 22-year-old Sarah has just resumed work on Modern Family which began production on series five last month. She tweeted before going to the premiere: "Had an amazon table read for #modernfamily this afternoon."
Sarah's also gearing up for the release of the trailer for her new movie Vampire Academy: Blood Sisters, and miniseries Bonnie & Clyde.
It has also just been announced she will star in and produce a new comedy drama called See You In Valhalla.