Lady Gaga Is Makeup-Free Celebrating Her 30th Birthday With Cake

Lady Gaga is glowing on her 30th birthday.

Lady Gaga appears to have celebrated her 30th birthday on Monday in super low-key fashion.

After previously celebrating at the No Name restaurant in West Hollywood, California, on Saturday night with her fiance, Taylor Kinney, and plenty of A-list pals, Gaga tweeted a selfie dressed in a comfy sweater on her actual birthday on Monday. The "Born This Way" singer flaunted her glowing skin in the makeup-free pic, and held up a delicious-looking slice of cake.

"I saved a piece of birthday cake my fans," she wrote. "You made my 20s worth it all. To spreading love, above all things."

WATCH: Adam Levine Tells Fans He Ate Cake Alone on His Birthday, Says It Might Have Been 'the Best' One Ever

"Thank you so much EVERYONE for all the beautiful birthday wishes," she also tweeted. "Feels good to be alive. Grateful for everyday God lets me live to see it."

The Oscar-nominated singer was the belle of the ball on Saturday night, when she rocked a show-stopping gold YSL mini-dress given to her by Saint Laurent creative director, Hedi Slimane, himself. Gaga hung out with Taylor Swift, Lorde, Kate Hudson, Nick Jonas, Lana Del Rey, Chrissy Teigen, John Legend, and more stars at the swanky soiree, partying past 3:30 a.m. at the exclusive club, sources told ET.

She spent Easter the next day with her family.

"Happy Easter! Time for family dinner," Gaga tweeted on Sunday. "Best cure for a Birthday Hangover. PRAYER."

WATCH: Lady Gaga and Taylor Kinney Pack on the PDA in Matching Western Outfits

Watch the video for more on Gaga's epic birthday celebration.