However, it wasn't the oversized bow or her killer statement flower earrings that caught our attention. It was, in fact, her date.
After walking the appropriately green carpet, Kate cuddled up to her boyfriend of seven months, musician Danny Fujikawa.
In a rare display of public affection, the actress shared a photo of their day date on Instagram. In the snap she latched onto his arm affectionately as they watched the polo match.
"Saturday fun in the ☀️" she captioned the adorable pic.
The couple also posed for photographers at the event, holding hands as they lounged on a lush white garden chair and drank delicious looking cocktails.
Since going public with their relationship in March this year, the pair have only shared a handful of photos on social media. See some of their sweetest moments below...