The birthday boy, who turned 27, was enjoying a low-key celebration with his rocker dad Ozzy, mum Sharon, sister Kelly and wife Lisa when they spotted their fellow Brits in the same eatery.
Soccer stud David Beckham and his designer wife Victoria stopped by their table to say hello and even posed for quick snaps with Kelly Osbourne, who promptly uploaded the photos to her Twitter.com account.
In the accompanying captions, she wrote, "Just ran into GoldenBalls (David) himself at dinner! Might I say he is looking rather dapper."
"But nothing beats running into one of my favorite fashion designers and friend @victoriabeckham".
The celebrity run-in capped off a fun-filled night for the Osbournes, who had arranged for Jack to be surprised with a special birthday cake, and Kelly concluded the meal by having her new sister-in-law Lisa take a picture of the rock clan.
Sharing the image with fans online, she tweeted, "Best family dinner ever!!!!"