When Williams takes on 11th-ranked Karolina Muchova on Monday night in Arthur Ashe Stadium, it will be her record-extending 25th appearance in the U.S. Open. It comes at the ripe age of 45, making her the oldest player to compete in singles at the U.S. Open since 47-year-old Renée Richards set the record in 1981.

Venus Williams will make her return to Grand Slam tennis at the U.S. Open in singles at age 45 after a two-year absence.

Venus Williams will be the first 45-year-old to compete at the US Open since 1981 when she faces Karolina Muchova on Monday.