Venus Williams walked off the court at Arthur Ashe Stadium to a standing ovation with a wave to the adoring crowd.

Will it be for the last time?

The second-oldest singles player in U.S. Open history, Williams didn’t get the fairytale upset.

But she delivered a turn-back-the-clock performance that showed the tennis world — and more importantly the 45-year-old herself — that she still can challenge the sport’s best if she wants to keep playing.

And she got a night to remember even if she doesn’t.

Williams, a wild card ranked just 602nd in the world, took 11th-seeded Karolina Muchova to a third set before falling 6-3, 2-6, 6-1 to the Czech.

And after soaking up the applause and the adulation, Williams, who has won seven Grand Slams, two of them here in Flushing Meadows, was noncommittal about where or if she’ll play again.

“Yeah, my goal is to do what I want to do,” Williams said. “I wanted to be here this summer. I’m so grateful for all the folks who gave me a wild card. They could’ve said, ‘Hey, listen, you’ve been gone too long. You haven’t won a lot of matches in the last few years.’ I wasn’t lucky with my health and with injuries.

“But there were a lot of people who believed in me in these tournaments. I’m very grateful to have had that chance and that opportunity to make good on it and have a chance to really strike the ball. … It’s a lot of fun to go literally hog wild out there and hit as hard as I can. I’m happiest when I can just hit hard.”

For Williams, it was a long road back, even at the end of an even longer career.

She underwent surgery for uterine fibroids and a subsequent health issue that was initially misdiagnosed as Sjogren’s syndrome.

It resulted in a 16-month layoff, and she just returned last month at the Citi Open in Washington, beating Peyton Stearns and losing her next three, including Monday to Muchova.

“The lights are very bright out there,” Williams said. “I don’t think I’ve ever had a crowd that much on my side. When I lost those first two games, they were just still right there with me every point. Didn’t matter if I was losing and it was starting to roll fast, they were just right there with me, and it felt great.

“I knew going into this match that people in this stadium, people in the United States, people around the world were really rooting for me, and that felt great. That felt great to have that kind of support.”

Williams became the oldest singles player at the U.S. Open since Renee Richards, 47, set the mark in 1981.

And the crowd urged Williams on, exhorting her after a slow start.

After going down 2-0, she reeled off the next three games and was up 40-30 on Muchova’s serve with a chance to break.

But she dropped the final four games of the set, with four double-faults in the last game alone.

Williams settled in and dominated the second set, serving better.

But she appeared to run out of gas in the third and final set against the Czech.

Still, she exceeded all reasonable expectations.

Was it enough to buoy her to play post-U.S. Open?

“Are there any tournaments in the States? Can someone move a tournament here? I don’t know that I’m willing to travel that far at this stage in my career to go play,” Williams laughed. “I love playing. The level of my game has come up so much since D.C. I tried as hard as I could to throw off any rust, but at the end of the day, there’s only so much that can really be accomplished in three or four matches.”

Pressed on if she has no plans, Williams replied: “Is there something? I don’t play in high altitude either, so I won’t be going to Guadalajara.”

With the next Grand Slam in Australia, Williams laughed, saying “That’s kind of far, too,” before becoming emotional and tearing up when asked what she’d proven to herself.

“For me, getting back on the court was about giving myself a chance to play more healthy. When you play unhealthy, it’s in your mind. It’s not just how you feel. You get stuck in your mind, too. So, it was nice to be freer.”