WASHINGTON, D.C. -- Martina Navratilova had a queasy feeling when she read that Venus Williams had accepted a main-draw singles wild card into the Mubadala Citi DC Open.

“I was thinking, 'Oh, this isn’t going to end well,’” the 18-time Grand Slam champion said Wednesday from her Miami home. “And how wrong was I? How wrong was I?”

As it turned out, about as wrong as possible.

At the age of 45, Williams was a forceful 6-3, 6-4 winner over Peyton Stearns to advance to a second-round match against No. 5 seed Magdalena Frech. That made Williams the second-oldest woman ever to win a tour-level singles match.

The first? Navratilova, who was 47 when she won a first-round match at Wimbledon in 2004.

“What can you say -- because it’s unbelievable,” Navratilova said. “She beat a top-ranked [No. 35] player. I mean, hats off.”

After winning her doubles match on Monday and singles on Tuesday night, Williams finally came back to earth. No. 2 seeds Taylor Townsend and Zheng Shuai were 6-4, 3-6, [10-6] winners over Williams and Hailey Baptiste. 

Before another packed house on John Harris Court, it was an entertaining match until the winner asserted themselves in the final frame. With a lunging Townsend volley, they converted their second match point.

Navratilova said she would have watched Williams’ singles match, but that she and wife Julia Lemigova had reservations at a Miami restaurant that couldn’t be canceled. Navratilova, of course, followed the score on her phone.

“Obviously, we both got some good DNA,” Navratilova said. “That the fast-twitch is still fast-twitching. Understanding the game, the geometry. Knowing how to play. All the mental stuff.

“We’re pretty similar that way. Focused, determined -- don’t take no for an answer.”

Navratilova was impressed at Williams’ level of fitness, which was lacking in her most recent outing last year in Miami and Indian Wells. Having to overcome Sjögren’s syndrome, the chronic autoimmune disease that saps strength and limits prolonged activity, she added, made it even more inspiring.

Twenty-one years ago, Navratilova was still an active doubles player but accepted a wild card into Wimbledon’s main singles draw. A decade after her last singles match, she defeated Catalina Castano 6-0, 6-1 before falling to Gisela Dulko in the second round.

After her breakthrough win, Williams cited the L-word.

“I think more than anything, it’s just about love, right?” she said. “If you have enough love for it, then you’ll put in the effort, and then you’ll find that little extra little bit at the end because I love it so much.”

Navratilova, unaware of those remarks, cited precisely the same premise.

“It just shows how much Venus loves the game,” Navratilova said. “Hope, perseverance, not quitting. Follow your path, just follow your path. If you’re on the path that you want to be on, that you love, you have everything to gain and nothing to lose, no matter what the result is, because you’re loving the path.

“Venus loves all of it, getting on the court. I hope she keeps going.”