There’s no crowd at the 2020 US Open to pull for Serena Williams and will her to victory so she provided her own encouragement in a tough fourth-round win on Monday.

“Keep fighting!” Williams exhorted herself.

Williams came back from a third-set deficit against Maria Sakkari, who she lost to less than two weeks ago, to prevail 6-3 6-7 (6-8) 6-3 to take another step closer to a record-equalling 24th grand slam title.

“I feel like I’m pretty vocal with or without a crowd. … I’m super passionate.,” Williams said after she advanced to the quarter-finals at Flushing Meadows for the 16th time.

“This is my job. This is what I wake up to do. This is what I train to do, 365 days of the year.

“Yeah, I’m always going to bring that fire and that passion and that ‘Serena’ to the court.”

When the match ended, after Williams collected six of the last seven games, she turned and yelled toward her husband, who stood at his front-row seat and yelled right back.

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How tight was this contest? Sakkari produced more aces than Williams, 13-12, and more total winners, 35-30.

Williams was two points from victory at 6-all in the second-set tiebreaker, but faltered there, sending a backhand return long to give Sakkari her fifth set point, then pushing a forehand out.

But as is so often the case, when the outcome was hanging in the balance in the third set, which Sakkari led 2-0 but couldn’t quite get to 3-1, Williams was better down the stretch, when it mattered the most.

“I have to be deadly honest, I wasn’t brave enough in the third set,” Sakkari said.

“I kind of like, not choked, but didn’t (convert) my chances.

“And if you don’t get your chances with a good Serena against you, it’s done.”

Six-times US Open winner Williams, who turns 39 in less than three weeks, will face unseeded Tsvetana Pironkova for a semi-final berth.

Playing in her first tournament in more than three years after taking time off to have a child, the 32-year-old Pironkova advanced with a 6-4 7-6 (7-5) 6-3 victory over Frenchwoman Alize Cornet.