Bella Hadid had the right sized uniform, but oversized equipment, as she took in some French Open action.

Bella rocked a miniskirt in her tight white Nike tennis outfit Saturday at Roland Garros Stadium while watching the Women's Singles Final. Jelena Ostapenko staged a huge comeback to beat Simona Halep.

Serena Williams didn't compete this year -- she's a little bit pregnant in case you haven't heard -- but was on hand to watch this week ... along with celebs like Lindsey Vonn, Hugh Grant, Alexander Skarsgard and Andre Agassi.