A Russian real-estate developer is suing a wedding planner-to-the-stars for botching her daughter’s ritzy Moscow wedding.

RI Group head Janna Bullock, who’s worth an estimated $700 million, hired celebrity event planner Tatiana Byron to orchestrate her daughter Zoe’s 2008 nuptials.

Byron, who’s worked with diva clients including Joan Rivers and Diana Ross, planned the $5 million, two-day celebration at a neoclassical Moscow mansion complete with horse-drawn carriages, embroidered napkins and a Tiffany registry.

But just 20 days before the ceremony, Byron quit — or was fired.

Bullock claims Byron could only speak “heavily accented” Ukrainian Russian, didn’t have her visa in order and hired a decorator who bolted after collecting $150,000. Then she walked off the job because she couldn’t handle the stress, according to Bullock. Byron claims she was fired after an argument over scheduling.

Bullock sued in 2012 for the return of Byron’s $50,000 fee plus additional damages. A Manhattan Supreme Court judge ruled this week that the case should go to trial.