Coco Gauff's revamped serve disposed slower deliveries, but supreme athleticism and bustling backhands helped her survive her first foe at the 2025 U.S. Open.

On the night that she debuted her new service motion, it was Gauff's tennis foundations that propelled her to victory.

Coco Gauff overcame 10 double faults and squandered chances to edge past Ajla Tomljanovic in three sets and reach the US Open second round