Serena eases into 4th round of US Open (photo credit: Getty Images)

Two-time US Open champion Venus Williams says she believes her sister, Serena, is on her way to winning her seventh US Open title.

Venus was beaten 6-1 6-2 by her younger sister in their 30th career meeting and she said Serena played ”untouchable tennis.”

“Whoever she plays, she’s going to earn it; it’s not like people don’t try. People will try against her,” Venus said.

The evening match at Arthur Ashe Stadium saw Venus succumb to her equal worst defeat at the hands of her sister.

Serena next faces Estonia’s Kaia Kanepi, who ousted top seed Simona Halep in the first round