Overview

• The main draw began Sunday under a new 15-day schedule, with a record $85 million purse and $5 million to each singles champion.
• Players voiced objections to the Sunday start, with Jessica Pegula noting the tight turnaround from the Cincinnati Open.
• Venus Williams, 45, lost 6-3, 2-6, 6-1 to No. 11 Karolína Muchová in her first-round return, marking her 25th US Open appearance and 101st match at the event.
• No. 6 seed and Australian Open champion Madison Keys was upset by Renata Zarazúa 6-7 (10), 7-6 (3), 7-5, tallying 89 unforced errors and 14 double-faults.
• Defending champion Jannik Sinner, labeled the odds-on favorite after two majors earlier this year, is slated to open his title defense on Tuesday.