By HOWARD FENDRICH Associated Press SEPTEMBER 2, 2015 — 8:30PM
Williams Williams speaks during a press conferene at the USTA Billie Jean King National Tennis Center in New York, Thursday, Aug. 27, 2015. (AP Photo/Kathy Willens)

NEW YORK – The enormity of what is at stake for Serena Williams at the U.S. Open — the first true Grand Slam in tennis since 1988 — hit her Wednesday.

That, she said, is why her play was so uneven in the second round, despite facing a qualifier ranked only 110th.

And it’s why, after the 10 double-faults, two dozen unforced errors and a sloppy first set, Williams listened to pointers from coach Patrick Mouratoglou and headed straight to a practice court to put in work, hoping to repair what plagued her in a 7-6 (5), 6-3 win over the Netherlands’ Kiki Bertens.

“Today, I was a little tight,” Williams said. “I think it showed.”

On Friday, Williams will meet Rochester native Bethanie Mattek-Sands in a third-round match. Mattek-Sands made it to the third round for the first time in 13 U.S. Open appearances by beating another American, CoCo Vandeweghe, 6-2, 6-1.
“You know what? Thirty is the new 21,” said Mattek-Sands, who turned 30 in March.

Mattek-Sands is best known in tennis for her original on-court outfits and her doubles success this year, winning the Australian Open and French Open with Lucie Safarova.

As for a fashion statement against Williams?

“I’ll have to see,” Mattek-Sands said, “what I’ve got packed in my bag.”