Canada's Rebecca Marino defeats Venus Williams in 1st round of Citi Open

Venus Williams lost to Canadian Rebecca Marino on Monday in her return to singles play after nearly a year away, a defeat the seven-time Grand Slam champion chalked up to being rusty.

"I didn't think I played well a lot of the time," Williams said. "Just trying to shake off some rust. That's just to be expected. All I can do is just play another tournament and play better."

Before the hard-court tune-up for the U.S. Open, Williams last played singles in Chicago on Aug. 23, 2021, when she lost to Su-Wei Hseih. Williams played mixed doubles with Jamie Murray at Wimbledon.

WATCH | Marino takes down Williams:

Williams practiced with sister and former doubles partner Serena leading up to the tournament, which is not routine for them.

"I think it was a real thrill for the crowd to see us hit together," Venus said. "I think more than anything, it was just very exciting for the tournament."

The 31-year-old Marino will advance to Wednesday's Round of 16.

An ace to close out a steely performance