NEW YORK — Get ready for the latest Grand Slam installment of Williams vs. Williams. One big difference this time: The superstar siblings will be meeting in the third round at the U.S. Open, their earliest showdown at a major tournament in 20 years.

Serena Williams set up the highly anticipated matchup at Flushing Meadows by hitting 13 aces and overwhelming 101st-ranked Carina Witthoeft of Germany 6-2, 6-2 in a little more than an hour in Arthur Ashe Stadium on Wednesday night. Hours earlier, across the way at Louis Armstrong Stadium, Venus Williams did her part with another straight-set victory, eliminating 40th-ranked Camila Giorgi of Italy 6-4, 7-5.

They will play Friday, and it is going to be their 30th tour-level encounter.

Both have been ranked No. 1. They have won a combined 30 Grand Slam singles trophies, 23 by Serena. They own eight U.S. Open singles titles.

Seeded women who advanced on another day with the temperature topping 95 degrees (33 Celsius) included No. 7 Elina Svitolina, No. 8 Karolina Pliskova, No. 15 Elise Mertens, No. 19 Anastasija Sevastova and No. 23 Barbora Strycova, all in straight sets.