The party, which celebrated 150 years of the Swiss luxury watch brand, was also attended by stars including Adriana Lima, Dev Patel and Karolina Kurkova.
The actress channelled her inner mermaid in a teal sequined gown with black lace detailing and an asymmetric hem, pairing the dress with black leather boots. Her blonde bob was styled with loose waves, and she added a bold orange-red lip colour to brighten the ensemble.
We're sure Roman won't forget his big night out with mum anytime soon!
This article originally appeared on InStyle Australia