NEW YORK—Venus Williams said the 6-1, 6-2, US Open demolition she suffered to Serena Williams was the best her younger sister has played in their 30-match rivalry.

Serena concurs.

More: Serena Slams Venus 

The 17th-seeded Serena, who moved into the US Open round of 16 for the 17th straight appearance, said tonight's third-round win was likely her best vs. Venus.

"I think it's by far the best match I ever played against her in forever," Serena said. "But I don't know about ever, ever. It probably was. I played much better tonight than I have since I started this journey on my way back."

Continuing her quest for an Open Era record seventh US Open crown, Serena now owns an 18-12 lead in the sisters' head-to-head series.

The 23-time Grand Slam champion said the sisterly showdowns are more mentally than physically demanding.

"For me it takes more mental energy than physical," Serena said. "It's not easy, but it is what it is. We started this journey 35 years ago, maybe less.

"Well, in a way, it started before we were born, so we started this journey a long time ago. We kind of knew what to expect. Even though it's difficult, especially for me, we just do the best that we can."

Photo credit: Mark Peterson/Corleve