Improved serve powers Gauff past Sonmez in US Open opener

Coco Gauff began her US Open campaign with a win, with the serve that had been a weakness now looking like a major weapon. The American's improved serving was a key factor in her Cincinnati Open title earlier this month, and analysis showed she is now striking closer to the line while keeping her usual speed.

Facing Sonmez, Gauff's new confidence was evident from the very first game. She hit a 112mph ace, followed by an unreturned first serve and another ace, holding to love in under 90 seconds. In the first set, Sonmez could rarely deal with Gauff's first delivery, and the world number four won 93% of points when she landed her first serve.

The second set brought a different challenge. Gauff broke early for a 1-0 lead, but her serve lost some effectiveness. Sonmez leveled at 2-2 and later held three break points for a 4-2 advantage. Yet Gauff responded with a precise ace out wide and a 115mph unreturned serve to hold, a moment she felt would have escaped her a year ago.

That gutsy hold shifted momentum. Gauff broke for 4-3 and then closed out the match with another confident service game. She hit three unreturned first serves, all just under 120mph, setting up three match points. Sonmez faltered on the first after a short rally.

Gauff later said that psychologically she now goes for the ace, knowing that most serves will not come back. She compared it to last year, when she simply hoped to get the serve in. Now she tries to hit 110, 115 or even 120mph almost every time. Next up for Gauff will be Paula Badosa or Daria Kastakina.