Coco Gauff credits superstar gymnast Simone Biles for helping bring a "bit of calm" as she finds a way to reach the US Open third round.

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