The former Buffy The Vampire Slayer star is preparing for a return to the small screen in new comedy Crazy Ones, co-starring Robin Williams.
36-year-old Sarah and Robin, 62, teamed up on the red carpet on Monday night (29 July) at the CBS/CW/Showtime Summer TCA Party in Los Angeles.
Sarah wowed in a LBD with a plunging back, teamed with black jewelled heels, an elegant up do and a statement red lip.
Crazy Ones, which will start in the US later this year, is about a father and daughter – played by Robin and Sarah – who work together in an advertising agency.
For Sarah, it's her first TV role since the drama Ringer, where she played identical twins. For Robin, it's his first TV role in more than 20 years (!) after his turn in Mork & Mindy.
Sarah, who has two children with husband Freddie Prinze Junior - Charlotte, 3, and Rocky, 10 months - recently said she was thrilled to be working in comedy again, something she had experience of from her time on Buffy.
"The one thing about Buffy that was so wonderful is we hit all of those different notes: It was funny, it was dramatic, it was scary, and ultimately, this is really what I wanted to do," she said.
"I think comedy is the most challenging. If you cry on camera, people feel for you. It's much harder to get someone to laugh."