Venus and Serena Williams will meet in the fourth round after both posted routine wins on Friday at the US Open.
Venus was again in impressive form as she saw off the threat of Daniela Hantuchova 6-3 6-3 under the lights.
Serena was below par for much of her third-round encounter with 25th seed Francesca Schiavone but proved too strong in the end, winning 6-3 6-4.
Serena has a narrow 7-6 lead in matches against her sister, but Venus was triumphant in Miami earlier this year.
"There's going to be a lot of hard hitting, a lot of hard serving," Venus predicted. "We'll both have a few tricks up our sleeves."
Serena was the first of the sisters to reach the last 16 and pronounced herself happy with her form after knee and ankle injuries.
"I think I'm playing OK," said the twice former champion.
"I definitely think I'm getting better and better. My knee's definitely feeling a lot better."
The junior Williams sister had lost to Schiavone in Rome back in May but took the upper hand on Firday by breaking in the seventh and ninth games to win the first set 6-3.
She broke again in the second set to go 4-2 up before a brief blip saw her lose her following service game. But she immediately bounced back to wrap up the contest.