The Big Bang Theory actress walked the red carpet at the Longines International Races Gala in Los Angeles on Thursday, marking her first formal appearance since announcing her split from husband Ryan Sweeting last week.
"She was in a really great mood, super happy and friendly, having a great time with her friends, laughing and joking and very relaxed," the source says. "She wasn't doing any press but was really friendly to everyone she met and seemed to be having a great night."
Since the split, Cuoco's been keeping busy. The actress gave her first post-split interview earlier this week at the Bryan Brothers Tennis Festival, which she attended in support of her longtime friends, tennis pros Bob and Mike Bryan.
"I love tennis and I love their foundation, so it means a lot to me," Cuoco told ET. "Bob and Mike have done so much for the sport of tennis in giving back in charities in Southern California and all over the world."
Cuoco grew up with the twin brothers in California, and it was the Bryans who set her up with her tennis-playing ex, Sweeting, in 2013. After three months of dating, the couple tied the knot on Dec. 31 and were together for 21 months. They were last seen together on Sep. 10.
Despite the split, Cuoco has not been letting heartbreak get her down. Just hours after the divorce announcement, the actress was photographed having a girls' night at The Village restaurant in Studio City, California. She and five friends, including her sister, Briana, were seen laughing and drinking wine while animatedly talking about Sweeting, according to an eyewitness.
Watch the video below to see more from Cuoco's night out.