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.

At 45 years old, Williams becomes the oldest player in the US Open singles tournament since Renee Richards (47) in 1981. While Williams is no longer considered a favorite, her past success is almost unparalleled. She has won seven singles and 14 doubles Grand Slam titles. Williams has two singles and two doubles titles at the US Open.

NEW YORK (AP) — It’s a given that much of the coverage and attention devoted to Venus Williams’ return to the U.S. Open, where play begins Sunday, has focused — and will focus — on how old she is. The American is, after all, 45, an age at which no one has competed in singles in New York since 1981.