Sistine, 18, worked the catwalk in an oversized black vest adorned with gold buttons and black heels.
"Thank you so much @stefanogabbana @dolcegabbana for always being so kind and generous. I am so unbelievably grateful for this opportunity. I ? my DG family??," she captioned a photo of her runway look on Instagram.
The Stallones weren't the only up-and-comers who rocked the runway, which epitomized Dolce & Gabbana's new social media hashtag, #DGMillennials. Lionel Richie's daughter, Sofia Richie, and social media star Cameron Dallas also strutted their stuff.
After the show, Stallone's oldest daughter continued to mingle with other DG Millennials, including Will Peltz, Neel Svisser and Cindy Crawford's son, Presley Gerber.